Question

Find the reference number for each value of
`t`.
(a)
`t=(5 \pi)/(4)`

Answer 1

Check the picture below.

the reference angle for any angle greater than 90° or π/2, is the angle made from the terminal point, with the horizontal axis, in this case, if we take the red terminal point and check what's the angle it makes with the horizontal, well, it'd be the same angle as you see there in green.