Question

prove the following cos²theta (1+tan²theta) = 1.​

Answer 1

Answer:

( 1 + $tan^{2}$theta = $sec^{2}$theA)

from identity $sec^{2}$theta - $tan^{2}$theta = 1

so substitute $sec^{2}$theA in place of 1 + $tan^{2}$theta

= cos²theta x $sec^{2}$theta = 1

Answer 2

Step-by-step explanation:

c

${cos}^{2}0 + (1 + {tan}^{2}0)$

cos^2A+ sec^2A

cos^2A +1/cos^2A

=1