Question

if tan 2A = cot ( A- 18 ) , where 2A is an acute angle , find the value of A ??

Answer 1

hey... MATE here's ur solution,
given,.

tan 2A = cot ( A - 18 )
cot ( 90 - 2A) = cot ( A -18 )
( since tan (90- Q = cot Q) )

90 - 2A = A - 18

- 2A - A. = -18 -90

hence A = 36

HOPE IT MIGHT BE HELPFUL !!

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 ☺