Sample Problems, Lesson 2.9
Sample Problems for this Lesson Course Home Page To the Notes Menu   Assignment  

2.9, #2, Given Problem.

2.9, #2, Given Problem.
Part (a).

Plot the function. If you were plotting the curve in Maple, 

>plot(ln(x),x=0..5,y=-2..2);

Along with this plot there is a sketch of a line tangent to the curve at (1,0).

It appears that the slope of the tangent line is approximately 1.

Part (b).

Using the slope-intercept form of a line and our approximate slope (m) of 1, we can get the linear equation for the tangent line at (1,0).
 

Part (c).

Here we use our linear approximation to find approximations for f (0.9) and f ( 1.3).

The estimates must be slightly high, because our tangent line is above the curve of the function.


2.9, #8, Given Problem.
 

2.9, #8, Given Problem.
 
Here we have a summary of the given information. We are to find an estimate for P when h = 3.
We calculate the average rate of change (slope) between the h = 1 and h = 2 data points.
Now using our approximate slope, we substitute in the latest data point (2,74.9) and find the y-intercept (b).
Now we have our linear approximation equation.
Using this equation, we can find out an approximation for when h = 3.

2.9, #14, Given Problem.
 
2.9, #14, Given Problem.
Part (a).

This table summarizes the given information, and shows the two values we want to find. I found the slope of 3 by using the g '(x) formula which was given.

We use our slope and substitute in our known data point of (2,-4) to find b.
Now we have our linear approximation model.
Using our model, we find approximations for g(1.95) and g(2.05).
Our estimates our slightly low.
We know this because from our g'(x) formula we can see that as x increases, g'(x) increases. This means the slope of our missing function is increasing (or concave up). Therefore, our linear estimate must be below the graph.


Assignment
1-11, Odds
Lesson 2.9, Pages 173-174

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