Question

IF TAN 2A=cot(a+60degree) ,find the value of A where 2A is an acute angle

Answer 1

We know tan Ф = cot(90-Ф)

So, In R.H.S, tan(90-a+60) = tan(30-a)

Now, tan 2a = tan (30-a)

2a = 30-a

3a=30

a=10....ANS

      

Answer 2

cot(90-2a) = cot(a+60)
90-2a = a+60
30 = 3a
a = 10
therefore 2a = 20