Issolvi cos(315)

$$\cos ( 315 )$$

Evalwa

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

Passi tas-Soluzzjonijiet

Uża \cos(x+y)=\cos(x)\cos(y)-\sin(y)\sin(x) fejn x=270 u y=45 biex tikseb ir-riżultat.

$$\cos(270+45)=\cos(270)\cos(45)-\sin(45)\sin(270)$$

Ikseb il-valur ta’ \cos(270) mit-tabella tal-valuri trigonometriċi.

$$0\cos(45)-\sin(45)\sin(270)$$

Ikseb il-valur ta’ \cos(45) mit-tabella tal-valuri trigonometriċi.

$$0\times \frac{\sqrt{2}}{2}-\sin(45)\sin(270)$$

Ikseb il-valur ta’ \sin(45) mit-tabella tal-valuri trigonometriċi.

$$0\times \frac{\sqrt{2}}{2}-\frac{\sqrt{2}}{2}\sin(270)$$

Ikseb il-valur ta’ \sin(270) mit-tabella tal-valuri trigonometriċi.

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

Agħmel il-kalkoli.

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