the following are equivalent sine ratios for one full standard angle rotation around an unit circle…

the following are equivalent sine ratios for one full standard angle rotation around an unit circle: \n$\\sin ( \\frac { \\pi } { 12 } ) = \\sin ( \\frac { 11 \\pi } { 12 } ) = \\sin ( \\frac { 13 \\pi } { 12 } ) = \\sin ( \\frac { 23 \\pi } { 12 } )$\ntrue\nfalse
Answer
Explanation:
Step1: Use the sine function property
The sine function has the property (\sin(\pi - \alpha)=\sin\alpha) and (\sin(2\pi-\alpha)=-\sin\alpha), (\sin(\alpha + 2k\pi)=\sin\alpha,k\in\mathbb{Z}). For (\sin\left(\frac{11\pi}{12}\right)), we have (\sin\left(\frac{11\pi}{12}\right)=\sin\left(\pi-\frac{\pi}{12}\right)). According to the formula (\sin(\pi - \alpha)=\sin\alpha), so (\sin\left(\pi-\frac{\pi}{12}\right)=\sin\frac{\pi}{12}). For (\sin\left(\frac{13\pi}{12}\right)), we have (\sin\left(\frac{13\pi}{12}\right)=\sin\left(\pi+\frac{\pi}{12}\right)). According to the formula (\sin(\pi+\alpha)=-\sin\alpha), so (\sin\left(\pi + \frac{\pi}{12}\right)=-\sin\frac{\pi}{12}). For (\sin\left(\frac{23\pi}{12}\right)), we have (\sin\left(\frac{23\pi}{12}\right)=\sin\left(2\pi-\frac{\pi}{12}\right)). According to the formula (\sin(2\pi-\alpha)=-\sin\alpha), so (\sin\left(2\pi-\frac{\pi}{12}\right)=-\sin\frac{\pi}{12}).
Answer:
False