CLASS XI HALF YEARLY MATHEMATICS 2020-21

 If A = {x: x is an odd natural number}, B = {x : x is a prime number}, find

 $A\cap B$  

• { x : x is an odd prime number}

• { x : x is a prime number}

• { x : x is a natural number}

• none of these

 Find the range of the function

 $f\left(x\right)\ =\ \frac{\left|x\right|}{x},\ x\ \ne0$  

• [ - 1, 1]

• { - 1, 0, 1 }

• { - 1, 1 }

• none of these

If A = {x, y, z} and B = {1, 2}, then find the number of relations from A to B.

• 6

• 32

• 64

• none of these

If (x+3, 4 – y) = (1,7), then find ( x – 3, 4 + y).

• -5 and 1

• (- 2, - 3)

• ( - 5, 1 )

• none of these

If sinA + sinB + sinC = 3, then find cosA + cosB + cosC

• 0

• 1

• -1

• none of these

Simplify

 $\frac{\sin x\ -\ \sin3x}{\sin^2x-\cos^2x}$  

• 2 cosx

• 2 sinx

• sinx 

• none of these

Find the value of

 $\tan\left(-\frac{16\pi}{3}\right)$  

•  $\sqrt{3}$  

•  $-\sqrt{3}$  

•  $\frac{1}{\sqrt{3}}$  

•  $-\frac{1}{\sqrt{3}}$  

 Find the modulus of the complex number

 $3+2i^{11}$  

•  $\sqrt{13}$  

•  $\sqrt{3}$  

•  $\sqrt{2}$  

• none of these

 Find the value of

 $\sqrt{-49}+\sqrt{-25}-3\sqrt{-16}$  

• 0

• i

• - i 

• none of these

Find the multiplicative inverse of

 $\left(2+\sqrt{3}i\right)^2$  

•  $\frac{1}{7}-\frac{4\sqrt{3}}{7}i$  

•  $\frac{1}{49}+\frac{4\sqrt{3}}{49}i$  

•  $\frac{1}{49}-\frac{4\sqrt{3}}{49}i$  

• none of these