Can anybody tell me how to solve for square roots

A33 gram sample of a substance that's used to detect explosives has a k-value of 0.1473. n = noekt no = initial mass (at time t = 0) n = mass at time t k = a positive constant that depends on the substance itself and on the units used to measure time t = time, in days

How can you tell when x and y are not directly proportional?

If tan2a=cot(a+60), find the value of a, where 2a is an acute angle