Question

11. Sin 4A = cos (A - 20"), where 4A is an acute angle, find the value of A
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Answer 1

Answer:

sin 4A = cos (A-20°)

cos (90°-4A) = cos (A-20°)

90°-4A = A -20°

A+4A= 90+20

5A = 110°

A= 110°/5

A=22°