Question

Sin²A-Cos²A=? Write the Short form

Answer 1

Step-by-step explanation:

चूँकि ( Sin²A + Cos²A = 1)

Sin²A - Cos²A = 1- Cos²A - Cos²A

= 1 - 2Cos²A

= -(2Cos²A - 1)

चूँकि ( Cos2A = 2Cos²A - 1)

= -Cos2A

Answer 2

Answer:

Step-by-step explanation:

We know that sin²Q+cos²Q=1••••••(1)

Let sin²Q-cos²Q=x••••••(2)

On adding (1) and (2) eq. we get,

2sin²Q=1+x

Sin²Q=1+x/2•••••••{3}

1-cos²Q=1+x/2

1-(1+x)/2=cos²Q••••••••{4}

On subtracting 3 from 4 eq. We get,

Sin²Q-cos²Q= 1+x/2-(1-(1+x)/2)

= 1+x/2-1+(1+x)/2

=1+x/2-2+1+x/2

=1+x-2+1+x/2

=2x/2

=x