Question

How do you find the value of cotθ if cosθ = -4/5?

Answer 1

First, find sin x.

`sin^2 x = 1 - cos^2 x = 1 - 16/25 = 9/25 -> sin x = +-3/5`

`cos x = -4/5`, then x is in Quadrant II, sin x is positive`(3/5)`

`cot x = cos x /sin x = (-4/5):(3/5) = -4/3`