Question

Write the first trigonometric function in terms of the second for θ in the given quadrant.
sec θ, sin θ; θ in quadrant I

Answer 1

1/sqrt(1-sin^2(theta)
but how do i get this

Answer 2

so

\[\sec(\theta) = \frac{1}{\cos(\theta)}\]



and \[\sin(\theta) = \cos(90 - \theta)\]

by the complementary angle rule

so \[\cos(\theta) = \sin(90 - \theta)\]

so use this to express

\[\sec(\theta)\] in terms of sin