Question

How do you evaluate `tan(arc cos - 3/5)`?

Answer 1

`-4/3`

Explanation:

`cos x = -3/5 --> x in quadrant 2.`
The side ratio of the triangle is --> 3:4:5
`cos x = (adjacent side)/(hypotenuse) = - 3/5`
`tan x = (opposite side)/(adjacent side) = 4/-3 = - 4/3`