The point P(5,0.8) lies on the curve y=4. If Q is the point (a, 4), find the slope of the secant line PQ for the following values of a. If a 5.1, the slope of PQ is: and if a 5.01, the slope of PQ is: 2. and if r=4.9, the slope of PQ is: 2. and if a 4.99, the slope of PQ is: Based on the above results, guess the slope of the tangent line to the curve at P(5,0.8).