Our teacher gave us some extra challenge questions and I've solved them all except for two, which has been really bugging me: 1) Determine the equation of a line that passses through (2,2) and is parallel to the line tangent to y=-3x^3-2x at (-1,5) 2) estimate the instantaneous rate of change of the surface area of a sphere with respect to its radius when the radius is 10cm. I don't want to know how to solve them but just a bit of help to get me along on my own would be nice. Thank you. EDIT: I just realized I put this in the wrong thread. Is it possible to move it to the Intro Calculus thread? Thank you.