Question

Select all angle measures for which sin(∅) = - ( (√2) /2)

a) 3π/4
b) 5π/4
c) 7π/4
d) 9π/4
e) 13π/4

I do not understand the steps to take, thank you for any help

Answer 1

B

C

D

Explanation:

Answer 2

b) 5π/4

c) 7π/4

e) 13π/4

Explanation:

sin θ = -½√2

There's really no algebra to be done here. There are two ways you can solve. One, you can use a calculator. Two, you can memorize your unit circle.

Either way, it helps to draw the unit circle. sin θ is the y coordinate, so you're looking for points on the circle where y = -½√2. This happens at two places: θ = 5π/4 and 7π/4.

Next, we need to check the options that are greater than 2π.

9π/4 is the same as π/4.

13π/4 is the same as 5π/4.

So the three correct answers are 5π/4, 7π/4, and 13π/4.