cos(240^circ)=-এর সমাধান করুন

$$\cos ( 240 ^ { \circ } ) =$$

মূল্যায়ন করুন

$$-\frac{1}{2}=-0.5$$

সমাধানের ধাপগুলো

Use \cos(x+y)=\cos(x)\cos(y)-\sin(y)\sin(x) where x=180 and y=60 to obtain the result.

$$\cos(180+60)=\cos(180)\cos(60)-\sin(60)\sin(180)$$

Get the value of \cos(180) from trigonometric values table.

$$-\cos(60)-\sin(60)\sin(180)$$

Get the value of \cos(60) from trigonometric values table.

$$-\frac{1}{2}-\sin(60)\sin(180)$$

Get the value of \sin(60) from trigonometric values table.

$$-\frac{1}{2}-\frac{\sqrt{3}}{2}\sin(180)$$

Get the value of \sin(180) from trigonometric values table.

$$-\frac{1}{2}-\frac{\sqrt{3}}{2}\times 0$$

গণনাটি করুন৷

$$-\frac{1}{2}$$