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

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

anonymous · Answer

(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

anonymous · Answer

oh yes (c)

cot(90 - θ)  = 1 / cot θ

anonymous · Answer

you ok with this?

anonymous · Answer

i'm told that part c is wrong

anonymous · Answer

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

anonymous · Answer

look at the diagram
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