CBSE Board Students Helpline

"Think on what you Learn :: In Physics Questioning every Answer is more important than answering Every Question" Learning without thinking deeply about it and not relating to already known facts is not permanent.Ask Questions about new concepts learned and don't rest until you get a satisfactory answer.Don't be shy in asking questions. "Only those questions are foolish which are not asked" You will find new dimensions and directions when you contemplate on what you learn or read.

1. Solve graphically 5x+2y=16, 7.5x+3y=24 (4) 2. Determine graphically the coordinates of the vertices of the triangle, the equations of whose sides are: y = x, 3y = x, x + y = 8 (4) 3. Solve graphically x – y = 10, 2x – 5y = 5 (4) 4. For what value of k will the equations x + 2y + 7 = 0, 2x + ky + 14 = 0 have one solution. (3) 5. Solve 4x + 6y = 3xy, 8x + 9y = 5xy given (x ¹ y, x ¹ 0) (3) 6. Solve given (x ¹ y, x ¹ 0) (3) 7. Solve each of the following system of equations by using the method of Cross Multiplication (a - b) x +

  Find the sum of 20 terms of the A.P. 1,4,7,10……… If the nth terms of an A.P is (2n + 1), find the sum of first n terms of the A.P. Find the sum of first 30 terms of an A.P.whose second term is 2 and seventh term is 22. Find the sum of first 10 terms of an A.P., in which 3 rd term is 7 and 7 th term is two more than thrice of its 3 rd term. Find the sum of all even integers between 2 to 100 divisible by 2. Find the number of terms in the series 20, 19 1/3 + 18 2/3 +………of which the sum is 300,explain the double answer. If the mth term of an A.P. is 1/n and the nth terms is 1/m, show that the sum of mn terms is ½(nm + 1). If the sum of n terms of an A.P.is same as the sum of its n terms, show that the sum of its (m + n) terms is zero. Find the sum of first n odd natural numbers. If the 8 th terms of an A.P.is 31 and the 15 th terms is 16 more than the 11 th terms find the sum of first 20 terms. How many terms of A.P.: 24,21,18,…….. Must be taken so that their sum is 78? The angl

  Find the sum of 20 terms of the A.P. 1,4,7,10……… If the nth terms of an A.P is (2n + 1), find the sum of first n terms of the A.P. Find the sum of first 30 terms of an A.P.whose second term is 2 and seventh term is 22. Find the sum of first 10 terms of an A.P., in which 3 rd term is 7 and 7 th term is two more than thrice of its 3 rd term. Find the sum of all even integers between 2 to 100 divisible by 2. Find the number of terms in the series 20, 19 1/3 + 18 2/3 +………of which the sum is 300,explain the double answer. If the mth term of an A.P. is 1/n and the nth terms is 1/m, show that the sum of mn terms is ½(nm + 1). If the sum of n terms of an A.P.is same as the sum of its n terms, show that the sum of its (m + n) terms is zero. Find the sum of first n odd natural numbers. If the 8 th terms of an A.P.is 31 and the 15 th terms is 16 more than the 11 th terms find the sum of first 20 terms. How many terms of A.P.: 24,21,18,…….. Must be taken so that their sum is 78?

Trigonometry (Assignment) Prove the following identities: If and show that < If prove that If prove that If prove that If find the value of If and show that If prove that If prove that Simplify: Evaluate: Evaluate: Evaluate: . If determine If Show taht If Show that If Show that If find the value of If find the value of If show that prove that If prove that If and prove that If prove that tan 35 0 tan 40 0 tan 45 0 tan 50 0 tan 55 0 tan 7 0 tan 23 0 tan 60 0 tan 67 0 tan 83 0 tan 5 0 tan 25 0 tan 30 0 tan 65 0 tan 85 0 Express sin 81 0 + tan 71 0 in terms of trigonometric ratios of angles between 0 0 and 45 0 . Express cos 75 0 + cot 75 0 in terms of trigonometric ratios of angles between 0 0 and 45 0 . If where are acute angles, find the value of . If A and B are acute angles and sin A = cos B, Prove that A + B = 90 0 . . If A, B, C are the interior angles of a triangle ABC, show that show that -----------