If -180o <= 180o , solve the equation
cos(2theta - 70o) = sin(theta+40o)
A good start would probably to apply sum and difference identities, so you can get and by themselves, and then work from there.
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And note also the double-angle identities:
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See where this leads....
If you get stuck please reply showing your steps and how far you have gotten. Thank you!
Type [tex]\theta[/tex].
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