Bihar Deled Maths Class 2026 | Bihar Deled Exam Analysis 2026 | Bihar Deled Maths Class By Uday Sir

[00:00:25]Miss Good Morning Good Morning Good Afternoon How are you?

[00:00:45]Yes, right in front, yes, the same five six, yes he is saying right, the volume of the cube is 1728 centimeters and tell me the length of its edge, sir, my maths is weak but I remembered the answers to all the questions through your analysis, that's all, we have to do, we have to crack the exam that is ahead of us and we should solve all its questions.

[00:01:14]Is it or not? Is our voice going properly? Come on.

[00:01:21]In today's set you have to give all the answers first.

[00:01:37]First of all, what is the volume of a cube? I am writing for side cube revision.

[00:01:44]Lateral Surface Area Lateral Surface Area 4a² Total Surface Area Total Surface Area 6a² and Diagonal 3a and What is this figure called? Cube is another name for it, dice.

[00:02:16]The exam is going on very deep, so maybe I can introduce one more name, hexahedron. The Hindi meaning of hexahedron is samset face.

[00:02:34]So what happens sometimes that if there is no information about the name then what happens to us in that situation also? A deception occurs.

[00:02:42]By the way, Ghan is a popular name. The question is asking what is the volume of the cube. Quantity means volume here so the value of a is 1728 1728 cube of what? So we will say cube of a means cube of 12.

[00:03:05]And the cube of 12 is 1728, so the cubes become equal.

[00:03:08]So this means what is the value of a? 12 Now some things have to be kept in mind in both cube and cuboid. Be it a cube or a cuboid, the edge in both is denoted by E. These are 12 faces which are also called surfaces and are denoted by f.

[00:03:40]Its number is six. There is a vertex which is called corner.

[00:03:50]Vertex is whatever is denoted by. Its number is eight.

[00:03:56]So Euclid gave a theorem which is also called Euclid algorithm.

[00:04:02]What theorems did Euclid give? So the theorem given is that the sum of vertex plus face will be two more than the edge.

[00:04:16]Which of the following statements is true? Or you can also write like this in the exam that tell the value of vertex plus face minus edge. So there is no need to get confused. Be it a cuboid or a cube.

[00:04:32]In both cases vertex plus face minus edge = 2 Bless everyone. Mother Goddess is making everyone's exams good. Your exam will also go well. No doubt. Ok? Come here.

[00:04:45]next question.

[00:04:48]A polynomial whose sum of roots i.e. alpha + beta zero is given.

[00:04:58]If one of the roots is three, what will be the other root? I do not know. So I would say what would be the value of beta? -3 Now we all know that whenever it comes to the rule of forming equations then x² - alpha + beta * x + alpha * beta = 0 here alpha and beta both are roots. Whose origin is it? The equation that comes out will have roots. Now tell me, I gave a value of alpha and the value of alpha is three. The value of a is beta whose value is given as -3, so x² - alpha + beta is automatically 0, so 0x and alpha * beta - 3 * 3 - 9 will be the answer, which will be x² - 9 = 0, that is, x² - 9 = 0, till here it is absolutely clear?

[00:06:14]Good afternoon. Good afternoon everyone. Let's take the next question.

[00:06:27]Ok? Even here.

[00:06:31]The question is saying that there is a circle whose radius is 5 cm. Is.

[00:06:41]Suppose this radius is 5 centimeters and this is also 5 centimeters. It meets at its tangent line i.e. at this place. Let's say its name is P. The centre is O.

[00:07:05]PQ and PR are tangents.

[00:07:10]So we're asked what the area of ​​this quadrilateral is? Now let us assume that we want to find the area of ​​a quadrilateral, then there is no such rule in mathematics that can find the area of ​​this quadrilateral. So what did we do in such a situation?

[00:07:27]Drew a line down the middle. As soon as you draw the line, a right angled triangle will be formed here.

[00:07:34]Because we all know that the radius and the tangent together form a right angled triangle and the length from this point to the center and to this point is given as 13. So the opposite of 90° is 13.

[00:07:49]That means the length of the hypotenuse is 13. One side of a right angled triangle is five. So 5 is the triplet of 12 and 13.

[00:07:59]So now if I ask who is this quadrilateral that you have? OQPR What will be the area of ​​this quadrilateral? There are two triangles in it. One triangle on the right, one triangle on the left, so the area of ​​one triangle is 1/2. Now multiply by because it is a right angled triangle, so the product of the sides forming the right angle is 5 * 12. If two and two are subtracted, then what will be 12 * 5? 8. So what will be its area?

[00:08:35]Its area will be 60 cm square. There is an exam tomorrow in Saharsa. All the best, everyone, give your exam well. Manasa Vacha Karmana Dhyana De Ke. Ok? All questions will be yours. The only difference is that while making the answer, you should not make any mistake in a hurry.

[00:08:56]Very beautiful. The question is asking, in which quadrant are the points I have -3 and four located? We all know that if there is any quadrant then it is divided into four parts. In this house i.e. first, x is also positive and y is also positive. And in the second quadrant x is negative and y is positive.

[00:09:24]In the third quadrant, x is also negative and y is also negative. Now in the fourth quadrant x positive, y negative. So in the point given to you, x is negative and y is positive. Meaning, in which quadrant will it fall? In the second quadrant, it is also called second quadrant in English.

[00:09:46]Also called the second quadrant.

[00:09:54]If you pay a little attention to the next question, you can solve it yourself.

[00:09:56]What is the question saying? The question says that a person buys some shares at the rate of ₹10 per share.

[00:10:04]We don't know how many shares he buys. So I assumed the number of shares was what? n and dividends are paid at the end of the year. So the cost of one share is ₹10. So, whatever number of shares he buys, when multiplied by 10, this will be his total investment.

[00:10:29]He will get 8% return on whatever amount he invested in the company, what do we call it, dividend, share of profit because a lot of people invest money in it. That is why the profit shares are small. And what is the rupee value of this dividend? ₹300 So if I ask the value of n then what will be the value of n? The value of n will be 8 * 3 = 24 8 * 7 = 56 8 * 5 = 40 375 like 4 * 2 = 8 if we subtract from four then 15 0 and 0 will be subtracted if we subtract from two sorry here it will be 25 15 I have written 25 and if we subtract from two then it will be 15 15 * 25 which is my children will be 375 so what will be your answer? 375 means in total he bought 375 shares and one share was worth ₹10. So his total investment was ₹3750 and on the investment of ₹3750, he earns a profit of 8% i.e. 8% of ₹3750 i.e. ₹300.

[00:11:49]Okay Nandit Nandlal Jatav, all the best, give your exam well son, give your exam with full dedication, everyone is ready, now the exam has come to the final stage, give your exam very well, if there are two rational numbers and if the LCM and MCF of both the rational numbers are equal, then suppose we take any two rational numbers and if both are equal, then their LCM will also be the same and HCF will also be the same. This is true. That is to say, if any two equal numbers are taken then their LCM will also be two and HCF will also be two. The condition is that the number should be rational. So what will be the answer? Similar. The length of a wire is reduced to 1/3.

[00:12:50]What does this mean? This means that if we assume that the length of the wire was three, then what will be the length of the wire now?

[00:12:59]One. What length will it be? Radius length. Now if I ask you that the radius of a wire becomes three to one then the volume.

[00:13:12]Now look carefully at the matter of height. Earlier it was in the form of a wire cylinder. It is still in the shape of a cylinder. So what was his before? πr² was h.

[00:13:25]What will happen now? πr² will become h.

[00:13:33]So π will be cut off. The value of r is one. Write forest here.

[00:13:45]* What is the value of h2 h2 equal to?

[00:13:51]How many times the old height? Nine times. What height is this? Old. So whatever the old height is, how many times will it be equal to?

[00:14:00]Equal to nine times. The wire is in the shape of a cylinder. The next question is asking that for the given quadratic equation, tell the ratio of the sum of its roots i.e. alpha + beta and the product of its roots i.e. alpha * beta. Well, what is the sum of the roots in any quadratic equation? -b/a Now what is the product of the roots? c/a then a and a will be cut then what will be your answer? -b So what value of b is appearing in the quadratic?

[00:14:55]What is the value of -5 and c shown? 3 So minus minus will become plus. So what about 5:3? The ratio will be What about 5:3? The ratio will be Exam is written below the name of the question.

[00:15:12]This means that there will be no change in the pattern. Of course, we will not say anything that will distract you.

[00:15:21]nobody. Come on, come.

[00:15:27]Go with a few things in mind. Will give work.

[00:15:30]First zero. What is zero? Neither negative nor positive.

[00:15:41]Listen carefully to the negative. Nither negative nar positive. It is neither positive nor negative.

[00:15:56]One smallest is the smallest natural number.

[00:16:03]Smallest prime number then sorry smallest natural number natural number is the smallest natural number.

[00:16:22]This one is also the smallest odd number. Least means the smallest odd number, least odd number, third one, memorize two lists, listen carefully to the list, it is a prime number, the smallest prime number starts from here and is the only number in the world which is prime as well as even.

[00:16:53]Only even prime three data, I understood point four, listen carefully, it is the least composite number, the smallest composite number, composite is known by two names. One is composite and the other is compound number.

[00:17:27]And six is ​​the smallest perfect number.

[00:17:32]Least perfect number means the smallest perfect number. Perfect number means perfect number.

[00:17:57]Ok. The biggest prime number is to keep things in mind right away. The largest prime and the smallest prime have to be found by digit. The smallest one digit prime is two and the divisor is the largest one digit is seven then 97 sorry the smallest two digit prime is 11 97 the smallest three digit prime is 1001 997 and the smallest four digit prime is 9973 and this 109 101 is not a small prime number. This is the smallest one digit smallest biggest two digit smallest biggest this is the smallest three digit largest and this is the smallest four digit largest.

[00:19:18]Ok? So keep some things in mind before going, it will work. Now let's come to the question.

[00:19:25]Smallest Prime Number So we know that the smallest prime number will be two and the smallest composite number will be four. So what will be the product of both? It will be eight. So once you have kept 2 * 4K 8 in mind, then write one more and go. Triangular number may be a triangular number may ask questions.

[00:19:55]Find the average of the first five triangular numbers.

[00:19:58]Despite it being an easy question. So 1 3 6 10 15 21 27 and so on, what will it be after 21? 21 7 28 Sense of saying this will be the smallest what? That means the triangle number will continue. Is this clear? I was watching the recorded video for so many days.

[00:20:23]Came live for the first time today. Okay, very good.

[00:20:27]Come on next question. Area of ​​a Rhombus We all know what a rhombus consists of? Please revise it a little.

[00:20:37]1/2 * the product of the diagonals d1 * d2 is the area.

[00:20:44]Whose area is it? of the rhombus.

[00:20:48]Robus is called Rombus in English. And what do you say in Hindi?

[00:20:53]Tell me by commenting. In Hindi it is called rhombus. That is, a quadrilateral whose four sides are equal to each other. Yes, it is not a square because all four angles are not 90°.

[00:21:08]Ok? The other arm side. If the side of any polygon is to be found then what will be 1/2 under root of a rhombus?

[00:21:22]t1² + t2² If we are asked about the perimeter, what will the perimeter be equal to? 4a 4 * 60 so the question that is given to me here is that the area of ​​the rhombus is given as 240, one diagonal is given as 16, the second diagonal is asking us the value of d2, so the value of d2 will come out to be 30, the value of d2 will become 30, yes the value of p2 will become 30.

[00:22:08]Everyone is right till here. Come next. is saying find the area of ​​the triangle formed by points A, B and C.

[00:22:25]First of all, if the area of ​​any triangle is to be calculated, then first of all the area of ​​the triangle is denoted by delta in coordinate geometry. So pay attention to the word area of ​​the triangle. First of all, you have to write 1/2. What to write first? 1/2.

[00:22:46]Ok? If anyone tells you the area of ​​a polygon, you can find it out. Pay attention.

[00:22:53]How much is the first vertex? g and 0 how much is the second vertex?

[00:23:03]How much is four and 0 the third vertex? 16 and eight. So if there is a triangle, it will have three vertices.

[00:23:09]If it is a quadrilateral then it will have four vertices. If it is a pentagon then there will be five vertices. So first you decorated the vertex and then what did you do? I rewrote the first one. Be it any quadrilateral, pentagon, heptagon or hexagon, whatever it may be.

[00:23:28]Now listen carefully from here. The arrow is going from top to bottom. This means that multiply these two and three and write them in one place. Like it was 1/2. At one place it is 6 * 0 4 * 8 32, what happened here? 16 * 0 0 difference.

[00:23:56]Now the arrow will move from bottom to top. The arrow will move from bottom to top. So multiply this at one place and add them together. Like multiply these three and add them. So how much is this? 4 * 0 16 * 0 0 6 * 8 48 Now only 48 came. The difference between these two results is 16. If the difference between them is 16 then the difference is always positive. So what will it become if we multiply 16 by 1/2? Eight i.e. 8 unit squares will be the area of ​​this triangle. By the way, those who are attending my regular discussions, we have also taught them how to create a vertex by zeroing it. It has also been taught to create a vertex by zeroing it.

[00:24:49]So you can calculate it like this also.

[00:24:56]And this crooked symbol is called difference. The slanted symbol is called the difference. And what is the area of ​​the triangle? It is positive. If for 10 seconds, suppose the area of ​​the triangle becomes zero, what will happen? Tell me quickly by commenting.

[00:25:19]So what will happen? So this will be called collinear.

[00:25:26]Then all three vertices will be collinear. And when I said collinear, I have repeated the same thing many times that there are many conditions for being collinear.

[00:25:38]One condition is that the slopes of both are equal. The second becomes ab + ac = 0.

[00:25:45]And the third area of ​​the triangle should become zero. So if the area of ​​a triangle becomes zero, then in such a case we say it is collinear. Well, keep one more thing in mind because when your exam is nearing its end, you have to keep a little bit in mind. The circle which is a circle is actually a polygon.

[00:26:10]is a polygon. What kind of polygon is it? So a polygon is a polygon with an infinite number of sides. There are an infinite number of sides.

[00:26:21]That is, it is a polygon with infinite sides.

[00:26:24]Keep one more thing in mind, the point which is there is also a circle.

[00:26:31]In whose category was the point placed? In the circle status.

[00:26:34]Someone asks what is the point? So is the circle.

[00:26:37]What kind of circle is it? Whose radius is zero.

[00:26:42]What is its radius? is considered to be zero.

[00:26:45]That is, the point is a circle whose radius is zero. And the second circle is a polygon which has infinite number of sides. Ok? And area of triangle zero means collinear.

[00:27:02]If 35 is removed from the given data, then by how much will the median of all the numbers 30, 34, 35, 36, 37, 38, 39 and 40 increase? When 30 comes after 34, 34 comes after 35, 35 comes after 36, 36 comes after 37, 35 comes after 38, 38 comes after 39 and 39 comes after 40.

[00:27:37]And when you remove 35, after 30 comes 34, after 34 comes directly 36. Then 37, then 38, then 39 and 40 what is the work of the median? First of all arrange it either in ascending order or descending order. Arrange in ascending order and descending order. And the number which is right in the middle of them, the total number of numbers in it is eight.

[00:28:11]So the child will have two numbers in the middle. If two numbers are given then the mean of both of them will be called the median. This means that when 35 was in your group, then in such a situation your median was 36 + 37 / 2 i.e. 36.5.

[00:28:35]And when you remove 35, there is only one number right in the middle, so now this will become the median of the new category.

[00:28:46]So now tell me one thing that as long as your median was 35, it was 37 and when 35 was removed from the median and the series, it became 37. So how much did it increase? There was an increase of 0.5. There was an increase of 0.5. Did you understand till here? Please comment quickly on the next question. Next question. What is the next question? tan theta / sec theta - 1 + tan theta / sec theta - + 1 So what's the first thing we did?

[00:29:25]tan theta taken common. What happens if you take tan theta as common?

[00:29:32]Look carefully, your LCM in the bottom will be sec theta -1 * sec theta + 1, this will be the LCM.

[00:29:47]Now let us talk about the fact that when we add fractions, if we divide it then it will come to the left. So what will come on the left? sec theta + 1 Now what goes to the right?

[00:30:00]sec theta - 1 Now tell me one thing this is tan theta if this -1 +1 of yours is subtracted then what will be left 2sec theta and what will happen below, look carefully what will happen when sec theta - 1 and sec theta + 1 are multiplied? sec² theta - 1 is the formula for what? The formula for tan² theta is.

[00:30:37]Now tell me one tan theta on top will cut two on the bottom. So what you got above is 2 * sec theta. We call 1 theta 1 / cos theta. And 1 tan theta is cut off at the bottom. There's a tan theta left over. So we're going to say 2sin theta over here divided by what? cos theta.

[00:30:59]Now you tell me, if cos theta is cut off then what is the value of 2 / sin theta and 2 / sin theta = 1 / sin theta? cosec theta What is the answer? 2 cosc ​​theta.

[00:31:17]What will be the answer to this? 2 cosc ​​theta.

[00:31:21]What will be the answer to this? 2 cosec theta.

[00:31:35]I'm back okay come next question is saying 6 tan square theta so let's take six I took common so here what will be left is tan² theta and 1/cos we will say sec square theta. There should be no mistake in Harbhari.

[00:32:10]Our rule of identity says that if sec² theta - 1, then sec square theta - tan² theta will be positive one. The rule says this but the condition I have says the opposite. This means we will have to take minus common. So 6 * -1, that's why there was a hurry brother, the temple became sindoor.

[00:32:38]What will be the answer? -6 Yes, one must have the eyesight of an eagle. Absolutely -6 very beautiful. Move ahead.

[00:33:00]Let's look at the next question carefully. Says the marked price of a machine is ₹6800.

[00:33:07]Ok? And if the marked price of the machine is ₹6800 then how much discount did you give on this marked price? By 10%. If you give a discount of 10% then you will sell the goods at 90%. That means you will sell it at 9/10 and multiply by another discount.

[00:33:27]So 100 - discount divided by how much? 100 final selling price is equal to how much? is equal to 5202. Now come one zero one zero has been cut. These were also cut.

[00:33:47]If I subtract from nine, then 9 * 5 = 45, 9 * 7 = 63 and 9 * 8 = 72. If I subtract from six, then 7 * 8 = 9, 11 * 6 = 66 and 74 is 6800, right? Yes, okay. 17 * 4 = 68 17 * 3 = 51 17 * 4 = 68 2 * 2 = 4 and 2 * 5 = 10 and if we divide by two then 17 so 17 * 5 = 85 then what will be the value of 100 - d? 85 then what will be the value of D?

[00:34:49]What percent is the value of 15% B? 15% Sir, please bless me. There is an exam tomorrow on 20th.

[00:35:00]Himanshu all the best to everyone. May Mother Goddess keep everyone happy and their minds calm. Please do give your exam well and come back. And remember, when the exam goes well, we deserve a like for our hard work.

[00:35:13]So please like, share and subscribe. If you ever remember in life, you will remember that there was someone there in the last moment.

[00:35:19]Yes, let's go, thank you. Love you all and give your exam well.

[00:35:26]Look what he is saying now. The question says the mode of the given data is six. When the mode is six, then six will appear the most number of times.

[00:35:36]So if here if here if there is six then the number six will become one six will become two six will become three. We cannot keep any other number.

[00:35:48]So what will be our answer? With accuracy.

[00:35:55]Yes.

[00:35:59]Ok.

[00:36:02]Difference between mode and median. Look, understand one thing, I have told you many times that the mode is denoted by z.

[00:36:14]What is the mode equal to? 3*median and -2*mean. We plug the mean outside of x and above.

[00:36:22]Now tell me, there is z here.

[00:36:26]If you take 1 m out of 3m here.

[00:36:30]2m will be saved here. So what does 2m mean?

[00:36:34]Median Now -2 mean so we took two common.

[00:36:38]Now the difference between the mode and the median is given as 12. If we divide this by two, then whose difference will be the remaining? The difference between the median and the mean will be How much difference will it make?

[00:36:53]Equal to six.

[00:36:57]And this is a very important relation to remember. I have discussed this many times. The value of the mean can be equal to the median and also equal to the mode and secondly the mean is always greater than the median and the median is always greater than the mode.

[00:37:13]Let's look at another question, what is it?

[00:37:18]4sin squared theta is 4sin² theta now minus what? The value of 4sin theta +1 is equal to 0. Indirectly, if we look at it indirectly, this is 2sin theta - 1 squared. a² - 2ab + b² which is equal to 0, then 2sinheta - 1 = 0, then what will be the value of sin theta, equivalent to 1/2 and which angle of sin theta gives 1/2, then 30°, so what will be the answer, children, the answer will be 30°, very easily. Okay sir, if someone else gives me quadratic then yes I will give it. If a quadratic equation is given, what should be done in such a case? Pay attention to the concept of b² - 4ac of class 10th, we calculate it like -b + - d/2a. The value of sin cos. I have told you the smallest prime number today. The smallest prime number is two. And the smallest compound number, I mentioned, is four. If the mass of these two is asking then what will happen to masses two and four? So sometimes I asked for addition and sometimes I asked for mass. So what is the answer equal to? This means I have to remember many things. Like today I told you in great detail what all the numbers are. Look at it.

[00:39:08]I told you 0 1 2 4 6, let me write one three also. If you say Sir, you did not write three, then three is the smallest least odd prime number.

[00:39:24]That is, the smallest odd prime number is three. The smallest odd one is one.

[00:39:32]But the smallest odd prime that exists is three.

[00:39:37]1 2 3 4 five taught na. Today someone will say that they do not teach from the basics. Come next. The question says that the sum of the three angles of a triangle is 4 3 7 2 9.

[00:39:51]What is the value of the ratio 9 equal to? The sum of the three angles of a 180° triangle is always 180 internally and 360 externally.

[00:40:01]So tell me what is the value of one? 20 ratio in degrees so 20 * 2 = 40 20 * 3 = 60 and 20 * 4 = 80 i.e. what will be my answer? 60 40 80 ok. There is nothing to do till here. The simplest way is that you have to go to the exam like this and keep your eyes wide open and come back smiling. Okay, all the best. Thank you so much. Love you all. See you again on Monday.

[00:40:49]Now the exam is on the verge of ending.

[00:40:51]Not even a single child complained. So my hard work was successful. Now how many of you have remaining exams?

[00:40:58]Come and see and enjoy. Have a lot of fun. Love you all. Good night. Take care. Bye-bye. Let go.

[00:41:04]You people will not be affected by this evil eye, right? Let go.