Calculus 1  Hour Exam 1   -   Math 220     Fall, 2010

 

1.

 

 

Given that  f(x)  =  2x3 + 5,  find a formula for  f -1(x).     Answer:  f -1(x)  =  [(x – 5)/2 ]1/3

 

 

2.

 

Suppose  f(x)  =  2 – ln x  and  g(x)  =  √x .  Determine a formula and find the domain

for  ( g of f) (x)   i.e.  g(f(x))

                                                    Answers:    g(f(x))  =  √( 2 – ln x)      Domain   ( 0, e2 ]

 

 

 

 

 

 

 

 

 

3.

 

 

Which one of the following equations must hold in order for a function  f  to be

continuous at a number  a?

 

a.       lim f(x)  =  a            b.  lim f(x)  =  0       c.  lim f(x)  =  f(a)

    xà0                              xà0                        xà0

 

d.      lim f(x)  =  f’(a)            e.  lim f(x)  =  a       f.  lim f(x)  =  0

    xà0                              xàa                        xàa

 

g.      lim f(x)  =  f’(a)            h.  lim f(x)  =  f’(a)       i.  lim f(x)  =  a

    xàa                              xàa                                  xà

 

j.        lim f(x)  =  f(a)            k.  lim f(x)  =  f(a)       l.  lim f(x)  =  f’(a)

    xà                              xà                               xà

 

Answer:  g

 

 

 

 

 

 

 

 

 

 

4.

 

 

Given a function f(x) for which lim  [ f(-5 + h) – f(-5)] / h exists, which one of the

following statements must be true?

 

a.  f is continuous but not differentiable at  x = -5

b.  f is differentiable but not continuous at  x = -5

c.  f is both continuous and differentiable at  x = -5

d. f is neither continuous nor differentiable at  x = -5

e.  f is continuous but not differentiable at x = 0

f.  f is differentiable but not continuous at x = 0

g.  f is both differentiable and continuous at x = 0

h.  f is neither continuous nor differentiable at x = 0

i.  f is continuous but not differentiable at x = 5

j.  f is differentiable but not continuous at x = 5

k.  f is both differentiable and continuous at x = 5

l.  f is neither continuous nor differentiable at x = 5                                  Answer:    c

 

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