Practice Problems

Work through the odd-numbered problems 1-17. Once you have completed the problem set, check your answers.

1. Use the function in Fig. 12 to fill in the table and then graph m(x).

x  y = f(x) m(x) = the estimated slope of the tangent line to y=f(x) at the point (x,y)
 0    
          0.5    
          1.0    
          1.5    
          2.0    
          2.5    
          3.0    
          3.5    
          4.0    


3. 

(a) At what values of x does the graph of f in Fig. 14 have a horizontal tangent line? 

(b) At what value(s) of x is the value of f the largest? smallest? 

(c) Sketch the graph of m(x) = the slope of the line tangent to the graph  of f at the point (x,y)


5. 

(a) Sketch the graph of f(x) = sin(x) for –3 ≤ x ≤ 10

(b) Sketch the graph of m(x) = slope of the line tangent to the graph of sin(x) at the point (x, sin(x))

(c) Your graph in part (b) should look familiar. What function is it? 


Problems 7 – 9 assume that a rocket is following the path y = x^2, from left to right. 

7. At what point should the engine be turned off in order to coast along the tangent line to a base at (5,16)

9. At what point should the engine be turned off in order to coast along the tangent line to a base at (1,3)



For each function f(x) in problems 11-15, perform steps (a)-(d):

(a) calculate \mathrm{m}_{\mathrm{sec}}=\frac{\mathrm{f}(\mathrm{x}+\mathrm{h})-\mathrm{f}(\mathrm{x})}{(\mathrm{x}+\mathrm{h})-(\mathrm{x})} and simplify

(b) determine \mathrm{m}_{\mathrm{tan}}=\lim _{h \rightarrow 0} \mathrm{~m}_{\mathrm{Sec}}

(c) evaluate \mathrm{m}_{\tan } at \mathrm{x}=2

(d) find the equation of the line tangent to the graph of \mathrm{f} at (2, \mathrm{f}(2))

11. f(x)=3 x-7

13. \mathrm{f}(\mathrm{x})=\mathrm{ax}+\mathrm{b} where \mathrm{a} and \mathrm{b} are constants

15. f(x)=8-3 x^{2}


In problem 17, use the result that if f(x)=a x^{2}+b x+c then m_{t a n}=2 a x+b.

17. \mathrm{f}(\mathrm{x})=\mathrm{x}^{2}+2 \mathrm{x} . At which point(s) (\mathrm{p}, \mathrm{f}(\mathrm{p})) does the line tangent to the graph at that point also go through the point (3,6)?


Source: Dale Hoffman, https://s3.amazonaws.com/saylordotorg-resources/wwwresources/site/wp-content/uploads/2012/12/MA005-3.1-Introduction-to-Derivatives.pdf
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