# Questions on Trigonometric Identities

Multiple choice questions on trigonometric identities with answers at the bottom of the page.

## Questions with Answers

### Question 1

Which of the following is not an identity?a) sin

^{2}a+cos

^{2}a = 1

b) sin a = tan a * cos a

c) 1 + cot

^{2}a = csc

^{2}a

d) 1 - sec

^{2}a = tan

^{2}a

### Question 2

Which of the following is an identity?a) sin (a) cos (a) = (1/2) sin(2 a)

b) sin a + cos a = 1

c) sin(-a) = sin a

d) tan a = cos a / sin a

### Question 3

^{2}t / sin t =

a) sin t

b) csc t

c) sec t

d) cos t

### Question 4

Which of the following is not an identity?a) tan(2 t) = 2 tan (t)

b) sin

^{2}a = 1 - cos

^{2}a

c) sin(-t) = - sin(t)

d) sec(-t) = sec(t)

### Question 5

Which of the following is an identity?a) sin

^{2}u = 1 + cos

^{2}u

b) cot u = sin u * cos u

c) sin

^{2}u = 1 - 1 / sec

^{2}u

d) cos(-u) = - cos u

### Question 6

a) -sin(x)

b) sin (x)

c) sec (x)

d) cos (x)

## Answers

- d)
- a)
- b)
- a)
- c)
- a)