Question

How do you find the cos of theta if sin of theta=1/4 and 0<theta<pi/2?

Answer 1

`cos t = sqrt15/4`

Explanation:

`sin t = 1/4` . Find cos t
Use trig identity: `cos^2 t = 1 - sin^2 t`
`cos^2 t = 1 - 1/16 = 15/16`
`cos t = +- sqrt15/4`
Since t is in Quadrant I, then, cos t is positive.
`cos t = sqrt15/4`