Question

Use the given function value, and trigonometric identities (including the cofunction identities), to find the indicated trigonometric functions.
sec θ = 5
(a) cos θ
(b) cot θ
(c) cot(90° − θ)
(d) sin θ

Answer 1

(a) use cos θ = 1 / sec θ

( b ) use cot θ = 1 / tan θ
and sec^2 θ = 1 + tan^2 θ

(d) use value of cos θ found in (a)
in sin^2 θ = 1 - cos^2 θ

Answer 2

oh yes (c)

cot(90 - θ) = 1 / cot θ

Answer 3

you ok with this?

Answer 4

i'm told that part c is wrong

Answer 5

hmm. - i did have to rack my brains with this one - long time...
i'll check

Answer 6

look at the diagram