(i) Find an equation for the line tangent to the graph of f1 at the point (3, 1) if f($) = $3 +2m2 $+ 1, (ii) Suppose f: R > R is such that f(3:+ y) = f($)f(y) for all $4,! 6 R, f is differentiable at zero, and fis not identically zero. Prove that f is differentiable everywhere and that f'(m) = f($)f'(0)