Question

prove the following trigonometric identities.
(1). (1+tan²0)cos²theta=1​

Answer 1

Step-by-step explanation:

$= (1 + { \tan}^{2} \alpha ) { \cos} ^{2} \alpha \\ = { \sec}^{2} \alpha \times { \cos}^{2} \alpha \\ = { \sec}^{2} \alpha \times \frac{1}{ { \sec }^{2} \alpha } \\ = 1hence \: proved...$