NEW
New Website Launch
Experience the best way to solve previous year questions with mock tests (very detailed analysis), bookmark your favourite questions, practice etc...
1

### IIT-JEE 1989

The general solutions of $$\,\sin x - 3\sin 2x + \sin 3x = \cos x - 3\cos 2x + \cos 3x$$ is
A
$$n\pi + {\pi \over 8}$$
B
$${{n\pi } \over 2} + {\pi \over 8}$$
C
$${\left( { - 1} \right)^n}{{n\pi } \over 2} + {\pi \over 8}\,\,$$
D
$$2n\pi + {\cos ^{ - 1}}{3 \over 2}$$
2

### IIT-JEE 1988

The value of the expression $$\sqrt 3 \,\cos \,ec\,{20^0} - \sec \,{20^0}$$ is equal to
A
2
B
$$2\sin {20^0}/\sin {40^0}$$
C
4
D
$$4\sin {20^0}/\sin {40^0}$$
3

### IIT-JEE 1987

The number of all possible triplets $$\left( {{a_1},\,{a_2},\,{a_3}} \right)$$ such that $${a_1} + {a_2}\,\,\cos \left( {2x} \right) + {a_3}{\sin ^2}\left( x \right) = 0\,$$ for all $$x$$ is
A
zero
B
one
C
three
D
infinite
4

### IIT-JEE 1986

The expression $$2\left[ {{{\sin }^6}\left( {{\pi \over 2} + \alpha } \right) + {{\sin }^6}\left( {5\pi - \alpha } \right)} \right]$$ is equal to
A
0
B
1
C
3
D
$$\sin \,4\,\alpha + \cos \,6\,\alpha \,\,\,\,$$

### 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