breen155
- 22
- 0
Hey, i need help with a problem I'm having I'm not sure about an expansion
Solve the following equation for -\pi<\theta<\pi
sin4\theta = cos2\theta
I'm not sure about how to expand sin4\theta
2. The attempt at a solution
I have tried putting sin4\theta as sin(2\theta+2\theta) and expanding to get sin2\thetacos2\theta + cos2\thetasin2\theta. However it just becomes very messy, I was just wondering if i am doing this correctly as the answer i receive is different to the one in my textbook
Homework Statement
Solve the following equation for -\pi<\theta<\pi
sin4\theta = cos2\theta
I'm not sure about how to expand sin4\theta
2. The attempt at a solution
I have tried putting sin4\theta as sin(2\theta+2\theta) and expanding to get sin2\thetacos2\theta + cos2\thetasin2\theta. However it just becomes very messy, I was just wondering if i am doing this correctly as the answer i receive is different to the one in my textbook