The point P(4,2) lies on the curve y = x^(1/2) . If Q is the point (x,x^(1/2)) , use your calculator to find the slope of the secant line PQ (correct to 6 decimal places) for the value x=3.99.
How would I approach this?
I think you'll find the slope does exist, and is not some huge number. 3.99 is not equal to 4, and you'll also see that the numerator is rather small as well. That's very typical of secant/tangent lines to smooth curves. You're always dealing with slopes that look like, or are close to, 0/0.