Finding Solutions for Sin 2θ = Sin θ in the Interval 0 ≤ θ ≤ 360?

[priscilla98]

Homework Statement

Find all values of θ in the interval 0 ≤ θ ≤ 360 that satisfy the equation sin 2θ = sin θ

Homework Equations

sin2θ = 2sinAcosA

The Attempt at a Solution

I'm a little confused on how to start off knowing sin2θ is equivalent to 2sinAcosA, would you factor this?

 

[Willian93]

sin2A = SinA
2SinAcosA = SinA
2SinAcosA - SinA = 0
SinA (2CosA-1)= 0
sinA = 0 2CosA-1=0
A= 0,180,360 A= 60, 300

i didn't check this, i just did this real quick, if i was wrong sorry, but i think i did it right
Hope that helps

 

[priscilla98]

Thanks a lot for this :)