Datrys sin5pi/4

$$\sin \frac { 5 \pi } { 4 }$$

Enrhifo

$$-\frac{\sqrt{2}}{2}\approx -0.707106781$$

Camau Ateb

Defnyddio \sin(x+y)=\sin(x)\cos(y)+\sin(y)\cos(x) lle mae x=\pi a y=\frac{\pi }{4} i gael y canlyniad.

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

Cael gwerth \sin(\pi ) o’r tabl gwerthoedd trigonometrig.

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

Cael gwerth \cos(\frac{\pi }{4}) o’r tabl gwerthoedd trigonometrig.

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

Cael gwerth \sin(\frac{\pi }{4}) o’r tabl gwerthoedd trigonometrig.

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

Cael gwerth \cos(\pi ) o’r tabl gwerthoedd trigonometrig.

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

Gwnewch y gwaith cyfrifo.

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