## Trigonometry 7th Edition

If $z = cos\theta - isin\theta$, then its absolute value $|z|$ = 1 (As proved in the step by step work)
If $z = cos\theta - isin\theta$, its absolute value $|z|$ will be, = $\sqrt{cos^2\theta + (-sin\theta)^2}$ = $\sqrt{cos^2\theta + sin^2\theta}$ = 1 (since according to Pythagorean identity, $cos^2\theta + sin^2\theta = 1$) Hence, if $z = cos\theta - isin\theta$, then its absolute value $|z|$ = 1.