Question

How do you find the value of `cot 135`?

Answer 1

Find `cot 135^@`

Explanation:

First way:
Trig Table of Special Arcs gives --> `cot 135^@ = - 1`
Second way:
`cot 135 = cos (135)/(sin (135))`
`cos 135 = cos (90 + 45) = cos 90.cos 45 - sin 90.sin 45 = - sqrt2/2`
`sin 135 = sin (90 + 45) = sin 90.cos 45 + sin 45.cos 90 = sqrt2/2`
`tan 135 = cos (135)/(sin (135)) = - (sqrt2/2)/(sqrt2/2) = - 1`
-