Question

1 - tan square A by 1 + tan square A is equal to 2 cos square A minus one​

Answer 1

=1- tan ² A/1 + tan ² A

=1- sin²A/cos²A/1+ sin²A /cos²A

=cos²A - sin²A/cos²A/cos²A+ sin²A/cos²

so,

= cos²A - (1- cos²A)/1

= 2cos²A - 1/+1

so, 2cos²A proved

Answer 2

Answer:

May be it helpful.......