When you go With X[t] : 1.2 t + Sin[t] and y[t] : 2 (1 + C0861), then as t advances from 0, {X[t], y[t]} sweeps out a curve: l 2 3 4 5 6 7 As you can see, this curve is the graph of a function y : f [X]. But it would be a Whale of a lot of trouble (in fact, it would be impossible) to find a clean formula for f [X]. In spite of this, calculate f' [X] by hand for: 1.27r i)X:X[721]: 7+1: 1.2\" N[ +1] 2 2.88496 ll)X=X[7T] = 1.27