Question

Prove that Cos²theta(1+tan²theta)=1

Answer 1

Answer:

Step-by-step explanation:

LHS= cos^2theta(1 +Tan^2theta)

      = cos^2theta(1+sec^2theta-1)     since (sec^2theta-tan^2theta=1)

      = cos^2theta(sec^2theta)

      =cos^2theta(1/cos^2theta)

      = 1

      =RHS

Hence Proved

Answer 2

cos²theta(1+tan² theta) = 1

cos²theta(1+sin²theta/cos²theta) = 1

cos²theta (cos²theta + sin²theta/cos²theta) = 1

cos²theta(1/cos²theta) = 1

1=1 LHS=RHS

HOPE IT HELPS...