Answer:
[tex]\text{sin}(\frac{\pi}{4})\text{ is correct option.}[/tex]
Step-by-step explanation:
[tex]\text{sin}(\frac{3\pi}{4})=\text{sin}(\pi-\frac{3\pi}{4})\ \ \ [\text{sin}\theta=\text{sin}(\pi-\theta)]\\\\\text{or, sin}(\frac{3\pi}{4})=\text{sin}(\frac{4\pi-3\pi}{4})\\\\\text{or, sin}({\frac{3\pi}{4})=\text{sin}(\frac{\pi}{4})[/tex]
