Question

True or false: the equation tan^2x+1=sec^2x

Answer 1

ANSWER

True

EXPLANATION

The given trigonometric equation is:

${ \tan}^{2} x + 1 = { \sec}^{2} x$

We take the LHS and simplify to arrive at the RHS.

${ \tan}^{2} x + 1 = \frac{{ \sin}^{2} x}{{ \cos}^{2} x} + 1$

Collect LCM on the right hand side to get;

${ \tan}^{2} x + 1 = \frac{{ \sin}^{2} x + {\cos}^{2} x}{{ \cos}^{2} x}$

This implies that

${ \tan}^{2} x + 1 = \frac{1}{{ \cos}^{2} x} .$

${ \tan}^{2} x + 1 = {( \frac{1}{ \cos(x) }) }^{2}$

${ \tan}^{2} x + 1 = { \sec}^{2} x$

This identity has been verified .Therefore the correct answer is true.