How do you find the remaining trigonometric functions of θ given cotθ=mn where m and n are both positive?

1 Answer
Apr 2, 2017

tanθ=nm

sinθ=oppositehypotenuse=nn2+m2

cosθ=adjacenthypotenuse=mn2+m2

cscθ=1sinθ=hypotenuseopposite=n2+m2n

sec=1cosθ=hypotenuseadjacent=n2+m2m

Explanation:

First let's identify the ones that are left.

tanθ,sinθ,cosθ,secθ,cscθ

But cotθ=1tanθ=adjacentopposite=mn

tanθ=oppositeadjacent=nm

Using the pythagorean theorem

hypotenuse2=opposite2+adjacent2

hypotenuse=opposite2+adjacent2

hypotenuse=n2+m2

sinθ=oppositehypotenuse=nn2+m2

cosθ=adjacenthypotenuse=mn2+m2

cscθ=1sinθ=hypotenuseopposite=n2+m2n

sec=1cosθ=hypotenuseadjacent=n2+m2m