Chapter 12
Precalculus: Mathematical for Calculus · 124 exercises
Problem 1
Find the slope of the tangent line to the graph of \(f\) at the given point. $$f(x)=3 x+4 \quad \text { at }(1,7)$$
3 step solution
Problem 1
Suppose that \(\lim _{x \rightarrow a} f(x)=-3 \quad \lim _{x \rightarrow a} g(x)=0 \quad \lim _{x \rightarrow a} h(x)=8\) Find the value of the given limit. If the limit does not exist, explain why. (a) \(\lim _{x \rightarrow a}[f(x)+h(x)]\) (b) \(\lim _{x \rightarrow a}[f(x)]^{2}\) (c) \(\lim _{x \rightarrow a} \sqrt[3]{h(x)}\) (d) \(\lim _{x \rightarrow a} \frac{1}{f(x)}\) (e) \(\lim _{x \rightarrow a} \frac{f(x)}{h(x)}\) (f) \(\lim _{x \rightarrow a} \frac{g(x)}{f(x)}\) (g) \(\lim _{x \rightarrow a} \frac{f(x)}{g(x)}\) (h) \(\lim _{x \rightarrow a} \frac{2 f(x)}{h(x)-f(x)}\)
8 step solution
Problem 1
Complete the table of values (to five decimal places) and use the table to estimate the value of the limit. $$\lim _{x \rightarrow 4} \frac{\sqrt{x}-2}{x-4}$$ $$\begin{array}{|c|c|c|c||c|c|c|} \hline x & 3.9 & 3.99 & 3.999 & 4.001 & 4.01 & 4.1 \\ \hline f(x) & & & & & & \\ \hline \end{array}$$
8 step solution
Problem 2
Find the slope of the tangent line to the graph of \(f\) at the given point. $$f(x)=5-2 x \text { at }(-3,11)$$
3 step solution
Problem 3
Find the limit. $$\lim _{x \rightarrow \infty} \frac{6}{x}$$
4 step solution
Problem 3
Complete the table of values (to five decimal places) and use the table to estimate the value of the limit. $$\lim _{x \rightarrow 1} \frac{x-1}{x^{3}-1}$$ $$\begin{array}{|c|c|c|c||c|c|c|} \hline x & 0.9 & 0.99 & 0.999 & 1.001 & 1.01 & 1.1 \\ \hline f(x) & & & & & & \\ \hline \end{array}$$
4 step solution
Problem 3
Evaluate the limit and justify each step by indicating the appropriate Limit Law(s). $$\lim _{x \rightarrow 4}\left(5 x^{2}-2 x+3\right)$$
6 step solution
Problem 3
Find the slope of the tangent line to the graph of \(f\) at the given point. $$f(x)=4 x^{2}-3 x \quad \text { at }(-1,7)$$
4 step solution
Problem 4
Find the limit. $$\lim _{x \rightarrow \infty} \frac{3}{x^{4}}$$
4 step solution
Problem 4
Evaluate the limit and justify each step by indicating the appropriate Limit Law(s). $$\lim _{x \rightarrow 3}\left(x^{3}+2\right)\left(x^{2}-5 x\right)$$
4 step solution
Problem 4
Find the slope of the tangent line to the graph of \(f\) at the given point. $$f(x)=1+2 x-3 x^{2} \quad \text { at }(1,0)$$
4 step solution
Problem 5
Find the limit. $$\lim _{x \rightarrow \infty} \frac{2 x+1}{5 x-1}$$
5 step solution
Problem 5
Complete the table of values (to five decimal places) and use the table to estimate the value of the limit. $$\lim _{x \rightarrow 0} \frac{\sin x}{x}$$ $$\begin{array}{|c|c|c||c|c|c|} \hline x & \pm 1 & \pm 0.5 & \pm 0.1 & \pm 0.05 & \pm 0.01 \\ \hline f(x) & & & & & \\ \hline \end{array}$$
7 step solution
Problem 5
Evaluate the limit and justify each step by indicating the appropriate Limit Law(s). $$\lim _{x \rightarrow-1} \frac{x-2}{x^{2}+4 x-3}$$
4 step solution
Problem 5
Find the slope of the tangent line to the graph of \(f\) at the given point. $$f(x)=2 x^{3} \quad \text { at }(2,16)$$
3 step solution
Problem 6
Find the limit. $$\lim _{x \rightarrow \infty} \frac{2-3 x}{4 x+5}$$
5 step solution
Problem 6
Evaluate the limit and justify each step by indicating the appropriate Limit Law(s). $$\lim _{x \rightarrow 1}\left(\frac{x^{4}+x^{2}-6}{x^{4}+2 x+3}\right)^{2}$$
6 step solution
Problem 6
Find the slope of the tangent line to the graph of \(f\) at the given point. $$f(x)=\frac{6}{x+1} \quad \text { at }(2,2)$$
5 step solution
Problem 7
(a) Estimate the area under the graph of \(f(x)=1 / x\) from \(x=1\) to \(x=5\) using four approximating rectangles and right endpoints. Sketch the graph and the rectangles. Is your estimate an underestimate or an overestimate? (b) Repeat part (a) using left endpoints.
5 step solution
Problem 7
Find the limit. $$\lim _{x \rightarrow-\infty} \frac{4 x^{2}+1}{2+3 x^{2}}$$
3 step solution
Problem 7
Use a table of values to estimate the value of the limit. Then use a graphing device to confirm your result graphically. $$\lim _{x \rightarrow-4} \frac{x+4}{x^{2}+7 x+12}$$
8 step solution
Problem 7
Find an equation of the tangent line to the curve at the given point. Graph the curve and the tangent line. $$y=x+x^{2} \quad \text { at }(-1,0)$$
4 step solution
Problem 7
Evaluate the limit and justify each step by indicating the appropriate Limit Law(s). $$\lim _{t \rightarrow-2}(t+1)^{9}\left(t^{2}-1\right)$$
4 step solution
Problem 8
(a) Estimate the area under the graph of \(f(x)=25-x^{2}\) from \(x=0\) to \(x=5\) using five approximating rectangles and right endpoints. Sketch the graph and the rectangles. Is your estimate an underestimate or an overestimate? (b) Repeat part (a) using left endpoints.
7 step solution
Problem 8
Find the limit. $$\lim _{x \rightarrow-\infty} \frac{x^{2}+2}{x^{3}+x+1}$$
4 step solution
Problem 8
Use a table of values to estimate the value of the limit. Then use a graphing device to confirm your result graphically. $$\lim _{x \rightarrow 1} \frac{x^{3}-1}{x^{2}-1}$$
5 step solution
Problem 8
Find an equation of the tangent line to the curve at the given point. Graph the curve and the tangent line. $$y=2 x-x^{3} \quad \text { at }(1,1)$$
4 step solution
Problem 8
Evaluate the limit and justify each step by indicating the appropriate Limit Law(s). $$\lim _{u \rightarrow-2} \sqrt{u^{4}+3 u+6}$$
6 step solution
Problem 9
(a) Estimate the area under the graph of \(f(x)=1+x^{2}\) from \(x=-1\) to \(x=2\) using three rectangles and right endpoints. Then improve your estimate by using six rectangles. Sketch the curve and the approximating rectangles. (b) Repeat part (a) using left endpoints.
7 step solution
Problem 9
Find the limit. $$\lim _{t \rightarrow \infty} \frac{8 t^{3}+t}{(2 t-1)\left(2 t^{2}+1\right)}$$
4 step solution
Problem 9
Use a table of values to estimate the value of the limit. Then use a graphing device to confirm your result graphically. $$\lim _{x \rightarrow 0} \frac{5^{x}-3^{x}}{x}$$
7 step solution
Problem 9
Evaluate the limit, if it exists. $$\lim _{x \rightarrow 2} \frac{x^{2}+x-6}{x-2}$$
4 step solution
Problem 9
Find an equation of the tangent line to the curve at the given point. Graph the curve and the tangent line. $$y=\frac{x}{x-1} \quad \text { at }(2,2)$$
3 step solution
Problem 10
(a) Estimate the area under the graph of \(f(x)=e^{-x}\) \(0 \leq x \leq 4,\) using four approximating rectangles and taking the sample points to be (i) right endpoints (ii) left endpoints In each case, sketch the curve and the rectangles. In each case, sketch the curve and the rectangles. (b) Improve your estimates in part (a) by using eight rectangles.
6 step solution
Problem 10
Find the limit. $$\lim _{r \rightarrow \infty} \frac{4 r^{3}-r^{2}}{(r+1)^{3}}$$
4 step solution
Problem 10
Use a table of values to estimate the value of the limit. Then use a graphing device to confirm your result graphically. $$\lim _{x \rightarrow 0} \frac{\sqrt{x+9}-3}{x}$$
6 step solution
Problem 10
Evaluate the limit, if it exists. $$\lim _{x \rightarrow-4} \frac{x^{2}+5 x+4}{x^{2}+3 x-4}$$
5 step solution
Problem 10
Find an equation of the tangent line to the curve at the given point. Graph the curve and the tangent line. $$y=\frac{1}{x^{2}} \quad \text { at }(-1,1)$$
5 step solution
Problem 11
Use the definition of area as a limit to find the area of the region that lies under the curve. Check your answer by sketching the region and using geometry. $$y=3 x, \quad 0 \leq x \leq 5$$
7 step solution
Problem 11
Find the limit. $$\lim _{x \rightarrow \infty} \frac{x^{4}}{1-x^{2}+x^{3}}$$
4 step solution
Problem 11
Use a table of values to estimate the value of the limit. Then use a graphing device to confirm your result graphically. $$\lim _{x \rightarrow 1}\left(\frac{1}{\ln x}-\frac{1}{x-1}\right)$$
7 step solution
Problem 11
Find an equation of the tangent line to the curve at the given point. Graph the curve and the tangent line. $$y=\sqrt{x+3} \text { at }(1,2)$$
4 step solution
Problem 11
Evaluate the limit, if it exists. $$\lim _{x \rightarrow 2} \frac{x^{2}-x+6}{x+2}$$
2 step solution
Problem 12
Use the definition of area as a limit to find the area of the region that lies under the curve. Check your answer by sketching the region and using geometry. $$y=2 x+1, \quad 1 \leq x \leq 3$$
7 step solution
Problem 12
Find the limit. $$\lim _{t \rightarrow \infty}\left(\frac{1}{t}-\frac{2 t}{t-1}\right)$$
7 step solution
Problem 12
Use a table of values to estimate the value of the limit. Then use a graphing device to confirm your result graphically. $$\lim _{x \rightarrow 0} \frac{\tan 2 x}{\tan 3 x}$$
6 step solution
Problem 12
Evaluate the limit, if it exists. $$\lim _{x \rightarrow 1} \frac{x^{3}-1}{x^{2}-1}$$
4 step solution
Problem 12
Find an equation of the tangent line to the curve at the given point. Graph the curve and the tangent line. $$y=\sqrt{1+2 x} \text { at }(4,3)$$
5 step solution
Problem 13
Find the area of the region that lies under the graph of \(f\) over the given interval. $$f(x)=3 x^{2}, \quad 0 \leq x \leq 2$$
5 step solution
Problem 13
Find the limit. $$\lim _{x \rightarrow-\infty}\left(\frac{x-1}{x+1}+6\right)$$
5 step solution