009A Sample Midterm 2

This is a sample, and is meant to represent the material usually covered in Math 9A for the midterm. An actual test may or may not be similar. Click on the  boxed problem numbers  to go to a solution.

 Problem 1 

Evaluate the following limits.

a) Find $\lim _{x\rightarrow 2}{\frac {{\sqrt {x^{2}+12}}-4}{x-2}}$

b) Find $\lim _{x\rightarrow 0}{\frac {\sin(3x)}{\sin(7x)}}$

c) Evaluate $\lim _{x\rightarrow ({\frac {\pi }{2}})^{-}}\tan(x)$

 Problem 2 

The function $f(x)=3x^{7}-8x+2$ is a polynomial and therefore continuous everywhere.

a) State the Intermediate Value Theorem.

b) Use the Intermediate Value Theorem to show that $f(x)$ has a zero in the interval $[0,1].$

 Problem 3 

Use the definition of the derivative to find ${\frac {dy}{dx}}$ for the function $y={\frac {1+x}{3x}}.$

 Problem 4 

Find the derivatives of the following functions. Do not simplify.

a) $f(x)=x^{3}(x^{\frac {4}{3}}-1)$

b) $g(x)={\frac {x^{3}+x^{-3}}{1+6x}}$ where $x>0$

 Problem 5 

The displacement from equilibrium of an object in harmonic motion on the end of a spring is:

$y={\frac {1}{3}}\cos(12t)-{\frac {1}{4}}\sin(12t)$

where $y$ is measured in feet and $t$ is the time in seconds. Determine the position and velocity of the object when $t={\frac {\pi }{8}}.$