For differentiable functions defined parametrically by x=f(t) and y=g(t), answer the following.
a. (i) Starting from x=f(t) and y=g(t), derive an expression for dxdy in terms of t. State clearly any conditions required for the formula to hold.
b. (ii) The curve C is given by x=3t−2,y=t2+1. Find the equation of the tangent to C at the point corresponding to t=2. Write the answer in slope–intercept form.
c. (iii) For the same curve C, determine all real values of t for which the tangent is parallel to the line y=4x+7. Hence obtain the equation of every such tangent.