find the equation of the tangent line T(x) to the graph of the given function at the indicated point. Use a graphing calculator to graph the function and the tangent line. 13) [T] y = 3x + 4x + 1 at (0, 1) 14) [T] y = 2x+1 at (4, 5) 15) [T] y = 16) [T] y = 2x x - 1 2 X at (-1,1) 3 x at (1,-1)