Given the depth vs. clock time function y = f(t) = .021 t² + -2.68 t + 87, with depth in cm when clock time is in seconds, find the clock time when water depth is 40.49523 cm. Using the same function determine the depth at clock time t = 12 sec. Find t such that f(t) = 63.49523. Find f(t) when t = 30.