Question

1=sec2theta - tan2theta tan2theta=sec2theta-1

Answer 1

1+tan²θ = sec²θ 

This is an identity.

This can be proved as following :-

1+tan²θ

= 1 + (sin²θ/cos²θ)

= (cos²θ + sin²θ)/cos²θ

= 1/cos²θ

= sec²θ 

Hence Proved.

Answer 2

1=1/cos^2theta - sin^2theta/cos^2theta

;1=1-sin^2theta/cos^2theta

;1=cos^2theta/cis^2theta
;1=1
again
tan^2theta=1/cos^2theta -1
tan^2theta=1-cos^2theta/cos^2theta

;tan^2theta=sin^2theta/cos^2theta

;tan^2theta=tan^2theta

proved

here is your answer...................