what is the exact value of $cotleft(\frac{3pi}{4}\right)$?\n-1\n$-sqrt{2}$\n1\n$sqrt{2}$

what is the exact value of $cotleft(\frac{3pi}{4}\right)$?\n-1\n$-sqrt{2}$\n1\n$sqrt{2}$
Answer
Explanation:
Step1: Recall cotangent formula
$\cot(x)=\frac{\cos(x)}{\sin(x)}$
Step2: Find $\cos(\frac{3\pi}{4})$ and $\sin(\frac{3\pi}{4})$
We know that $\cos(\frac{3\pi}{4})=-\frac{\sqrt{2}}{2}$ and $\sin(\frac{3\pi}{4})=\frac{\sqrt{2}}{2}$
Step3: Calculate $\cot(\frac{3\pi}{4})$
$\cot(\frac{3\pi}{4})=\frac{\cos(\frac{3\pi}{4})}{\sin(\frac{3\pi}{4})}=\frac{-\frac{\sqrt{2}}{2}}{\frac{\sqrt{2}}{2}}=- 1$
Answer:
A. -1