cos3pi/4 eching

$$\cos \frac { 3 \pi } { 4 }$$

Baholash

$$-\frac{\sqrt{2}}{2}\approx -0,707106781$$

Yechim qadamlari

Natijani olish uchun x=\frac{\pi }{2} va y=\frac{\pi }{4} boʻlganda, \cos(x+y)=\cos(x)\cos(y)-\sin(y)\sin(x) formulasidan foydalaning.

$$\cos(\frac{\pi }{2}+\frac{\pi }{4})=\cos(\frac{\pi }{2})\cos(\frac{\pi }{4})-\sin(\frac{\pi }{4})\sin(\frac{\pi }{2})$$

Trigonometrik qiymatlar jadvaldan \cos(\frac{\pi }{2}) qiymatini oling.

$$0\cos(\frac{\pi }{4})-\sin(\frac{\pi }{4})\sin(\frac{\pi }{2})$$

Trigonometrik qiymatlar jadvaldan \cos(\frac{\pi }{4}) qiymatini oling.

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

Trigonometrik qiymatlar jadvaldan \sin(\frac{\pi }{4}) qiymatini oling.

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

Trigonometrik qiymatlar jadvaldan \sin(\frac{\pi }{2}) qiymatini oling.

$$0\times \frac{\sqrt{2}}{2}-\frac{\sqrt{2}}{2}\times 1$$

Hisoblarni amalga oshiring.

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