prove that sin(3x)=3sinx-4sin^3x
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Use the fact Then use formula. Of course remember and
Hello, polymerase! Here it is . . . in baby-steps. Prove that: . We're expected to know these identities: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Another approach: Identifying the real parts and the imaginary parts we have
Originally Posted by red_dog Another approach: Identifying the real parts and the imaginary parts we have nice! how do you come up with this stuff?!
Originally Posted by Jhevon nice! how do you come up with this stuff?! This is actually a well known trick. To find . Use de Moiver's Theorem. So, . Apply Binomial Expansion on RHS.
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