Let f(x)=x+3. Find the slope of the secant line from x = 1 to each of the following a values. Round answers to 5 decimal places. From x = 1 to x = 0.9: From x = 1 to x = 0.99: From x = 1 to x = 0.999: From x = 1 to x = 1.1: From x = 1 to x = 1.01: From x = 1 to x = 1.001: Based on the above results, estimate the slope of the tangent line to f(x) at (1,4).