Doug C. answered 02/22/21
Math Tutor with Reputation to make difficult concepts understandable
The idea is to let the x coordinate of point Q get closer and closer to 1 (from both sides).
So pick x coordinate values for point Q like 1.01, 1.001, 1.0001, .9, .99, .999. Determine the y-value(s) of point Q then calculate the slope PQ. See if those slopes are approaching a value. That value is the slope of the tangent line to the curve.
See the following graphs to get the idea:
desmos.com/calculator/wpiaogjz2n
desmos.com/calculator/u8dvdt8fyi
Doug C.
If you take a look at the 2nd Desmos graph and the table of values you will see that the values are approaching -44. The actual value is -14pi. If you are not sure how to visit Desmos, select the 2nd URL above, right-click and choose "go to...". The blue line on the graph is the actual tangent line.02/22/21
Doug C.
Here is actually a better graph for illustrating how the slope of a secant line approaches the slope of a tangent line as the change in x gets small. If you visit this graph you will see "sliders" for a and h. Leave the a value alone, use the "h" slider to make h get smaller and smaller. When you do that you will see red line (secant) getting closer and closer to the green line (tangent). If you do change "a" that will move the point of tangency. desmos.com/calculator/w5ml2w37l302/23/21
Sofia B.
Thank you very much!! :)02/23/21
Sofia B.
Thank you so much. Is it possible if you can clarify the final answer as well. Thank you once again.02/22/21