1

### IIT-JEE 1998

Which of the following number(s) is /are rational?
A
$$\sin {\mkern 1mu} {15^ \circ }$$
B
$$\cos {\mkern 1mu} {15^ \circ }$$
C
$$\sin {\mkern 1mu} {15^ \circ }{\mkern 1mu} \cos {\mkern 1mu} {15^ \circ }$$
D
$$\sin {\mkern 1mu} {15^ \circ }{\mkern 1mu} \cos {\mkern 1mu} {75^ \circ }$$
2

### IIT-JEE 1998

The number of values of $$x\,\,$$ in the interval $$\left[ {0,\,5\pi } \right]$$ satisfying the equation $$3\,{\sin ^2}x - 7\,\sin \,x + 2 = 0$$ is
A
0
B
5
C
6
D
10
3

### IIT-JEE 1996

$${\sec ^2}\theta = {{4xy} \over {{{\left( {x + y} \right)}^2}}}\,$$ is true if and only if
A
$$x + y \ne 0\,$$
B
$$x = y,\,x \ne 0$$
C
$$x = y\,$$
D
$$x \ne 0,\,y \ne 0$$
4

### IIT-JEE 1995

The minimum value of the expression $$\sin \,\alpha + \sin \,\beta \, + \sin \,\gamma ,\,$$ where $$\alpha ,\,\beta ,\,\gamma$$ are real numbers satisfying $$\alpha + \beta + \gamma = \pi$$ is
A
positive
B
zero
C
negative
D
-3

### 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