74. Investigation Let P(xo, yo) be an arbitrary point on the graph of f such that f'(x) # 0, as shown in the figure. Verify each statement. (a) The x-intercept of the tangent line is (xo - f (xo) 0). f' ( x 0 ) (b) The y-intercept of the tangent line is (0, f(xo) - xof'(xo)). Th C (c) The x-intercept of the normal line is (x, + f(x) f'(x), 0). XO (d) The y-intercept of the normal line is ( 0, yo + f' ( xo )