## Trigonometry 7th Edition

$(\cos\theta)^{2}$
For ease we express squares of trigonometric functions as following- $(\cos\theta)^{2}$ = $\cos^{2}\theta$ This indicates we mean to square the number that is the cos of $\theta$. or $(\tan\theta)^{2}$ = $\tan^{2}\theta$ This indicates we mean to square the number that is the tan of $\theta$.