18. given $sin\\theta$, write $sin(-\\theta)$. $sin60{}^{\\circ }=\\frac{\\sqrt{3}}{2}$
18. given $sin\\theta$, write $sin(-\\theta)$. $sin60{}^{\\circ }=\\frac{\\sqrt{3}}{2}$
Answer
Explanation:
Step1: Use the trigonometric identity for sine of negative angle
The identity is $\sin(-\theta)=-\sin\theta$.
Step2: Substitute $\theta = 60^{\circ}$
Since $\sin60^{\circ}=\frac{\sqrt{3}}{2}$, then $\sin(-60^{\circ})=-\sin60^{\circ}$.
Answer:
$\sin(-60^{\circ})=-\frac{\sqrt{3}}{2}$