Question

Cos2a is equal to



Find first number send me the answer please please please

Answer 1

ANSWER:

hope this is what u want

Answer 2

ANS]

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➡$cos2a = {cos}^{2} a - {sin}^{2} a$

➡$cos2a = 2 {cos}^{2} a - 1$

➡$cos2a = 1 - 2{sin}^{2} a$

➡$cos2a = \frac{1 - {tan}^{2}a }{1 + {tan}^{2} a}$

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