Q. 13 E4.3( 11 Votes )
If sec 5A = cosec (A + 36°) and 5A is a positive acute angle, let us find the value of A.
Answer :
Given, sec5A = cosec(A + 36°)
And 5A is positive acute angle
⇒ sec5A = cosec(A + 36°)
⇒ cosec(90° - 5A) = cosec(A + 36°)
[secθ = cosec(90 - θ)]
⇒ 90 - 5A = A + 36
⇒ 90 - 36 = 6A
⇒ 6A = 54
⇒ A = 9
Hence, the value of A is 9
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