- #1
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 -[tex]\pi[/tex]<[tex]\theta[/tex]<[tex]\pi[/tex]
sin4[tex]\theta[/tex] = cos2[tex]\theta[/tex]
I'm not sure about how to expand sin4[tex]\theta[/tex]
2. The attempt at a solution
I have tried putting sin4[tex]\theta[/tex] as sin(2[tex]\theta[/tex]+2[tex]\theta[/tex]) and expanding to get sin2[tex]\theta[/tex]cos2[tex]\theta[/tex] + cos2[tex]\theta[/tex]sin2[tex]\theta[/tex]. 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 -[tex]\pi[/tex]<[tex]\theta[/tex]<[tex]\pi[/tex]
sin4[tex]\theta[/tex] = cos2[tex]\theta[/tex]
I'm not sure about how to expand sin4[tex]\theta[/tex]
2. The attempt at a solution
I have tried putting sin4[tex]\theta[/tex] as sin(2[tex]\theta[/tex]+2[tex]\theta[/tex]) and expanding to get sin2[tex]\theta[/tex]cos2[tex]\theta[/tex] + cos2[tex]\theta[/tex]sin2[tex]\theta[/tex]. 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