cos135^circ-এর সমাধান করুন

$$\cos 135 ^ { \circ }$$

মূল্যায়ন করুন

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

সমাধানের ধাপগুলো

Use \cos(x+y)=\cos(x)\cos(y)-\sin(y)\sin(x) where x=90 and y=45 to obtain the result.

$$\cos(90+45)=\cos(90)\cos(45)-\sin(45)\sin(90)$$

Get the value of \cos(90) from trigonometric values table.

$$0\cos(45)-\sin(45)\sin(90)$$

Get the value of \cos(45) from trigonometric values table.

$$0\times \frac{\sqrt{2}}{2}-\sin(45)\sin(90)$$

Get the value of \sin(45) from trigonometric values table.

$$0\times \frac{\sqrt{2}}{2}-\frac{\sqrt{2}}{2}\sin(90)$$

Get the value of \sin(90) from trigonometric values table.

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

গণনাটি করুন৷

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