# 11th CBSE Mathematics Assessment 2019

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March 24, 2021
11th Class, CBSE Question Papers, Mathematics
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**School Name: Himalaya Public School, Sector 13, Rohini, Delhi 110085 India**

Time: 40 minutes

**Marks: **20

**Class: 11th Class**

**Date: 20/08/2019**

## NCERT 11th Class CBSE Mathematics Assessment 2019

### All questions are compulsory:

**Question**: 1. If Sin A = 3/5 and cos B = 9/4, O < A< π/2, O < B < π/2 find the value of Cos (A – B). [2]

**Question**: 2. Convert (π/8) radian into degree measure. [2]

**Question**: 3. Prove that: Sin 20° Sin 40° Sin 60° Sin 80° = 3/16 [4]

**Question**: 4. Prove that: (Cos *x* – Cos *y*)² + (Sin x – Sin y)² = 4 Sin² *x*–*y*/2 [4]

**Question – 11th Mathematics Assessment 2019**: 5. Prove that: tan 3*x* tan 2*x* tan *x* = tan 3*x* – tan 2*x* – tan *x *[4]

**Question**: 6. If tan *x* = -4/3, π/2 <*x* <π, find the value of Sine *x*/2, Cos *x*/2 and tan *x*/2. [4]