Precalculus : Sum and Difference Identities For Tangent

Study concepts, example questions & explanations for Precalculus

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Example Questions

Example Question #1 : Sum And Difference Identities

According to the trigonometric identities, \(\displaystyle 1+cot^2(x)=?\)

Possible Answers:

\(\displaystyle tan(x)\)

\(\displaystyle \frac{sin(x)}{cos(x)}\)

\(\displaystyle \frac{1}{tan(x)}\)

\(\displaystyle csc^2(x)\)

\(\displaystyle 1\)

Correct answer:

\(\displaystyle csc^2(x)\)

Explanation:

The trigonometric identity \(\displaystyle 1+cot^2(x)=csc^2(x)\), is an important identity to memorize.

Some other identities that are important to know are:

\(\displaystyle \frac{sin(x)}{cos(x)}=tan(x)\)

\(\displaystyle cot(x)=\frac{1}{tan(x)}\)

\(\displaystyle sin^2(x)+cos^2(x)=1\)

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