Question

If tan A=1 find sin2A + cos2A

Answer 1

If tan A=1

Then sin A=1/(2)^(1/2)

CosA=1/(2)^(1/2)

Sin2A=2sinAcosA=1/2

Cos2A=cos^2(A)-sin^2(A)=0

Therefore sin2A+cos2A=1/2

Answer 2

Answer:

Given,

    tanA=1

   sin2A+cos2A=?

we know,

   sin2A=2tanA/1+tan^(2)A

   cos2A=1-tan^(2)a/1+tan^(2)A

solution,

         =sin2A+cos2A

        =2tanA/1+tan^(2)A + 1-tan^(2)a/1+tan^(2)A

        =2.1/1+1^(2)+1-1^(2)+1+1^(2)

        =2/2+0/2

        =1+0

        =1