How do I prove that
(1+sin2x) = (cosx)
(cosx + sinx) (cosx - sinx)
I can't tell what you need to prove, since what you have written is ambiguous. Put parentheses around the terms in each numerator and in each denominator.
Do you know any double angle identities?
I know double angle identities such as
sin2x = 2sinxcosx and the three cos2x ones but i cant get anything to work
I've got all the formulas but i dont know how to use them to make it work
Dude, i got pissed off at this same question yesterday. The key is 1 +2sinxcosx is a perfect square!!!
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