Higher Math 2nd Paper MCQ-Dhaka Board-2017

1. What is the value of midterm of the expansion of $\left(x-\frac{1}{x}\right)^{8}$

2. $\alpha$ be the angle between the two forces $5 p$ and $4 p$. What is the value of $\alpha$ when $\sqrt{21} p$ is resultant force?

3. $\cot \theta=k$. Its solution is $\theta=n \pi+\alpha$.

What is the value of $\theta$ when $k=1$ and $\frac{\pi}{4}<\theta<2 \pi ?$

4. Which is the square root of $i$ ?

5. Which is the argument of $i$ ?