Question

find sin theta and cos theta if cot theta = 3/7 and sec theta is < 0

Answer 1

cotθ = 7/3 = y/x
If secθ = r/x < 0, then x<0 and y<0, so θ is in QIII
In QIII, both sinθ and cosθ < 0
r^2 = x^2 + y^2, so r = √40
sinθ = y/r
cosθ = x/r
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