Réitigh sin(5pi/8)

$$\sin ( \frac{ 5 \pi }{ 8 } )$$

Luacháil

$$\frac{\sqrt{\sqrt{2}+2}}{2}\approx 0.923879533$$

Céimeanna Réitigh

Bain úsáid as \sin(x+y)=\sin(x)\cos(y)+\sin(y)\cos(x) nuair atá x=\pi agus y=\frac{\pi }{4}ann chun an toradh a fháil.

$$\sin(\pi +\frac{\pi }{4})=\sin(\pi )\cos(\frac{\pi }{4})+\sin(\frac{\pi }{4})\cos(\pi )$$

Faigh luach do\sin(\pi )ón dtábla luachanna triantánúla.

$$0\cos(\frac{\pi }{4})+\sin(\frac{\pi }{4})\cos(\pi )$$

Faigh luach do\cos(\frac{\pi }{4})ón dtábla luachanna triantánúla.

$$0\times \frac{\sqrt{2}}{2}+\sin(\frac{\pi }{4})\cos(\pi )$$

Faigh luach do\sin(\frac{\pi }{4})ón dtábla luachanna triantánúla.

$$0\times \frac{\sqrt{2}}{2}+\frac{\sqrt{2}}{2}\cos(\pi )$$

Faigh luach do\cos(\pi )ón dtábla luachanna triantánúla.

$$0\times \frac{\sqrt{2}}{2}+\frac{\sqrt{2}}{2}\left(-1\right)$$

Déan áirimh.

$$-\frac{\sqrt{2}}{2}$$