Prove the following statement: $$1+\tan^2a=\dfrac{1}{\cos^2a}$$
I tried but I failed to find answer cause I don't know how to prove trigonometric equalities.
Thank you for your help!
Prove the following statement: $$1+\tan^2a=\dfrac{1}{\cos^2a}$$
I tried but I failed to find answer cause I don't know how to prove trigonometric equalities.
Thank you for your help!
Hint:
$$\color{blue}1+\color{red}{\tan^2a}=\color{blue}{\dfrac{\cos^2a}{\cos^2a}}+\color{red}{\dfrac{\sin^2a}{\cos^2a}}$$