Question

1. Which of the following are identities? l. sin(-x) = -sin xll. cos(-x) = cos xlll. tan(-x) = -tan xIV. cos(-x) = -cos x. A. l, lll, and IVB. lll and IVC. l, ll and lllD. ll only

Answer 1

C. l, ll, and lll

Step-by-step explanation

We want to find the options that are trigonometric identities.

Trigonometric identities are equalities that are true for both sides for any value of the variable involved in the function.

From the options given, the trigonometric identities:

`\begin{gathered} \sin (-x)=-\sin x \\ \cos (-x)=\cos x \\ \tan (-x)=-\tan x \end{gathered}`

The correct answer is option C.