Which of the following is the strongest Lewis acid?

Which of the following properties does not support the anomalous behavior of boron?

$\sinh(ix)$ is equal to

Which property of alkaline earth metals increases with their atomic number?

$\int \frac{1+\cos 4 x}{\cot x-\tan x} d x$ is equal to

$A$ particle is projected from the ground with an initial speed of $v$ at an angle of projection $\theta$. The average velocity of the particle between its time of projection and the time it reaches the highest point of its trajectory is