UnScramble this Word: o a b e a n s l?

Questions

branch of mathematics concerned with the study of such concepts as the rate of change of one variable quantity with respect to another, the slope of a curve at a prescribed point, and the computation of the maximum and minimum values of functions?

heavier-than-air craft that derives its lift not from fixed wings like those of conventional airplanes, but from a power-driven rotor or rotors, revolving on a vertical axis above the fuselage?

what latin word is used for information of little use?

of sin, cos or tan, which graph is not differentiable at all points?

with what acid do nettles cause irritation?