A) tanx · cosx + cotx · sinx = sinx +cosx Please I really need help! The question is asking to prove the identity.

Can someone answer this question? : )

Hurry which expression is equivalent to 3√x^5y?

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?