Question

the value of 2cosA​

Answer 1

cos(A+B)=cosAcosB−sinAsinB(1)(1)cos⁡(A+B)=cos⁡Acos⁡B−sin⁡Asin⁡B

cos(A−B)=cosAcosB+sinAsinB(2)(2)cos⁡(A−B)=cos⁡Acos⁡B+sin⁡Asin⁡B

Adding (1)(1) and (2),(2), we have

cos(A+B)+cos(A−B)=2cosAcosB.cos⁡(A+B)+cos⁡(A−B)=2cos⁡Acos⁡B.

Answer 2

Answer:

The value of 2cosA is :-

Cos ( A + B ) + Cos ( A - B )

Step-by-step explanation:

Hope it helps

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