Question

show that tan²theta -1/cos²theta =-1​

Answer 1

Step-by-step explanation:

to prove tan²θ -1/cos²θ =-1​

take LHS

= tan²θ -1/cos²θ

= tan²θ -sec²θ

= - (sec²θ - tan²θ)

= -1

= RHS

=> LHS = RHS

Hence proved