From sin(3θ) = −1/sqrt2, Solve for 3θ on the interval [0,2pi).

Question

From sin(3θ) = −1/sqrt2, Solve for 3θ on the interval [0,2pi). Enter your answers on a comma separated list.

3θ=

θ=

Answer 1

let x=θ

sin(3x)=-1/√2

sin(3x)=-√2/2

look on the unit circle

sin is -√2/2 at 225° and at 315°

therefore θ=225/3=75° and θ=315/3=105º

3θ=225º and 315º

θ=75º and 105º