Complete the sentence so the result is an identity. Let x be any real number.
-$- 1 = \tan ^ { 2 } x$
A) $\cos ^ { 2 } x$
B) $\cot ^ { 2 } x$
C) $\sec ^ { 2 } x$
D) $\sin ^ { 2 } x$

Question

Quizplus · Accepted Answer

The identity $-1 = \tan^2x + \cos^2x$ is incorrect. The correct trigonometric identity that relates to $\tan^2x$ is $1 + \tan^2x = \sec^2x$. Therefore, rearranging for $-1 = \tan^2x$ gives $\tan^2x = \sec^2x - 1$, which matches the identity $1 + \tan^2x = \sec^2x$.

Complete the Sentence So the Result Is an Identity −1=tan⁡2x- 1 = \tan ^ { 2 } x−1=tan2x

Complete the Sentence So the Result Is an Identity $- 1 = \tan ^ { 2 } x$