Question

(A + 45) = ¹√2 (cos A-sin A)prove that
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Answer 1

GIVEN

(A + 45) = ¹√2 (cos A-sin A)prove that

ANSWER

multiplying and divide LHS √2

√2 (1/√2 sin A + 1/√2 cos A)

and sin 45 = cos 45 = 1/√2

=> √2 ( sin 45 sin A + cos 45 cos A)

=> √2 cos(45-A )