Trigonometric Identities

IMPORTANT

Trigonometric Identities: Overview

This topic covers concepts such as Pythagorean Identities for Trigonometric Functions, Trigonometric Identities, Trigonometric Identities for Compound Angles, Expansion of sin(A±B), Expansion of cos(A±B), Expansion of tan(A±B), etc.

Important Questions on Trigonometric Identities

MEDIUM
IMPORTANT

If cosθcosec23° = 1, then find the value of θ.

MEDIUM
IMPORTANT

What should come in the place of (?) for the given expression?

9sec2θ  9tan2θ=?

HARD
IMPORTANT

Let  f(x)=sin6x+cos6x+k(sin4x+cos4x)  for some real number k, then the value of k for which f(x) is constant for all values of x is

EASY
IMPORTANT

Which of the following is the simplest form of given function:

   tan 1 [ cosxsinx cosx+sinx ],x<π.

HARD
IMPORTANT

For 0<ϕ< π 2 , if x=n=0cos2nϕ, y=n=0sin2nϕ, z=n=0cos2nϕsin2nϕ, then

MEDIUM
IMPORTANT

If   α+β= π 2 and   β+γ=α , then   tanα  equals –

MEDIUM
IMPORTANT

  3 ( sinxcosx ) 4 +6 ( sinx+cosx ) 2 +4( sin 6 x+ cos 6 x )  equals to 

EASY
IMPORTANT

The value of the expression   3 cosec20°sec20° is equal to

MEDIUM
IMPORTANT

( 1+cos π 8 )( 1+cos 3π 8 )( 1+cos 5π 8 )( 1+cos 7π 8 ) is equal to –

MEDIUM
IMPORTANT

Which of the following numbers is rational?

HARD
IMPORTANT

The expression   3[ sin 4 ( 3π 2 α )+ sin 4 ( 3π+α ) ]2[ sin 6 ( π 2 +α )+ sin 6 ( 5πα ) ]  is equal to

MEDIUM
IMPORTANT

Find value of cos2π8.

EASY
IMPORTANT

Find the value of cos2212°-sin2212°cos2212°+sin2212°

EASY
IMPORTANT

If tanA+cotA=5, then tan4A+cot4A is equal to

EASY
IMPORTANT

If cosecθ+cotθ=6, then which one of the following is true?

EASY
IMPORTANT

The least value of 2sin2θ+3cos2θ is 

HARD
IMPORTANT

Find the  expansion of con(nx) and sin(nx) using complex numbers

HARD
IMPORTANT

If fθ=1-sin2θ+cos2θ2cos2θ, then value of f11°f34° equals-

MEDIUM
IMPORTANT

A vertical pole stands at a point A on the boundary of a circular park of radius a and blinds an angle α at another point B on the boundary. If the chord AB subtends an angle α at the centre of the park, then the height of the pole is