What is the sine value of 7 pi over 6?
Since \(\sin(\pi-x)=\sin x\), you have\(\sin\dfrac{7\pi}6=\sin\left(\pi-\dfrac{7\pi}6\right)=\sin\left(-\dfrac\pi6\right)\)and since \(\sin x\) is odd, i.e. \(\sin(-x)=-\sin x\), you have\(\sin\dfrac{7\pi}6=-\sin\dfrac\pi6=-\dfrac12\)
