how do I go about solving the first part of this problem

1. [5/10 Points] DETAILS PREVIOUS ANSWERS MY NO Let P be a point on the graph of y=e-x10 with NONZERO x-coordinate a. The normal line to the graph through P will have y-intercept b. (Note: The normal line at P is perpendicular to the tangent line at P. P X (0,b) (a) Calculate lima-> 0 b= Enter the number, -infinity, infinity or DNE (does not exist). (b) Calculate lima- 0 b= - Oo Enter the number, -infinity, infinity or DNE (does not exist). Submit Answer Viewing Saved Work Revert to Last Response