Question

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

Answer 1

cot(90-2A)=cot(A-18)
comparing both side we get
90-2A=A-18
90+18=2A+A
108=3A
A=36
Hope u understand

Answer 2

Tan(2A) can be written as cot(90-2A)
Therefore
90-2A=A-18
3A=108
A=36