IntroCal / Mr. Hansen

Name: ________________________

1/30/2007

 

 

Quiz (50 points)

 

1.

For g(x) = cos(ln x), answer these questions.

 

 

(a)

g¢(x) = ______________________________

 

 

(b)

Oops! This was my mistake. Explain why x = 0 is technically not a “critical value.”

 

 

 

 

 

 

(c)

Explain why x = 1 is a “critical value.”

 

 

 

 

 

 

(d)

Find the smallest critical value that is greater than 1. (Give exact value, no decimals.)

 

 

 

 

 

 

 

 

 

 

 

 

(e)

State g(ep/4) in exact form (no decimals).

 

 

 

 

 

 

(f)

Prove that (e2p, 1) is a local maximum.

 

 

 

 

 

 


 

2.

For the function y = f (x) = x/(x2 + 1), answer these questions.

 

 

(a)

Find an equation of the tangent line that passes through (1, ½).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(b)

State Df, the domain of f.

 

 

 

 

(c)

State Df ¢ , the domain of f ¢.

 

 

 

 

(d)

Find all critical points of f without using your calculator. (Show work.) State the type (local min., local max., etc.) for each one.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3.

Is it possible for a function f to have a critical point where f ¢(x) = 0, but where (x, f (x)) is neither a local minimum nor a local maximum? Explain.