1

### IIT-JEE 1987

Fill in the Blanks
The sides of a triangle inscribed in a given circle subtend angles $$\alpha$$, $$\beta$$ and $$\gamma$$ at the centre. The minimum value of the arithmetic mean of $$cos\left[ {\alpha + {\pi \over 2}} \right],\,\cos \left[ {\beta + {\pi \over 2}} \right]$$ and $$cos\left[ {\gamma + {\pi \over 2}} \right]$$ is equal to _______.

$${{ - \sqrt 3 } \over 2}$$
2

### IIT-JEE 1987

Fill in the Blanks
The solution set of the system of equations $$X + Y = {{2\pi } \over 3},$$ $$cox\,x + cos\,y = {3 \over 2},$$ where x and y are real, is _____.

$$\phi$$
3

### IIT-JEE 1981

Fill in the Blanks
Suppose $${\sin ^3}\,x\sin 3x = \sum\limits_{m = 0}^n {{C_m}\cos \,mx}$$ is an identity in x, where C0, C1 ,....Cn are constants, and $${C_n} \ne 0$$ , then the value of n is _____.

6

### Joint Entrance Examination

JEE Main JEE Advanced WB JEE

### Graduate Aptitude Test in Engineering

GATE CSE GATE ECE GATE EE GATE ME GATE CE GATE PI GATE IN

NEET

Class 12