Question

if tan2A=cos(A-18degree) where 2A is on acute angle, find the value of A.

Answer 1

Hii friend.....
tan2A = cot(A-18°)
cot(90°-2A) = cot(A-18°)
So,90°-2A = A -18°
90°+18 = A +2A
108° = 3A
A = 36°
THANKS
HOPE IT HELPS U☆☆☆

Answer 2

 Solution:

It is given that tan2A=cot(A−18°)

 ⇒tan2A=cot(90° −(108° −A))

⇒tan2A=tan(108° −A)        

{°•° cot(90° −A)=tan(A)}

 ⇒2A=108° −A

 ⇒3A=108°

 ⇒A=108°/3 =36°

Thanks ☺