If the terminal side of an angle theta contains the point (-1,3), find secant theta.

Answer 1

You should memorize the trig ratios is terms of x, y and r
so for the point (-1,3)
x = -1, y = 3 and by Pythagoras, r = √10

cosθ = x/r = -1/√10
and since secθ = 1/cosθ

secθ = -√10