To find an antiderivative of
f(
p), we go through
our list of integration methods:
- Recognize elementary antiderivatives
- Rewrite the integrand to make it easier
- Use substitution to reverse the chain rule or simplify the
integrand
- Use integration by parts
- Use inspection to see the value of a definite
integral
to find one that works for this integrand. In this case,
only one method is appropriate. We use substitution to rewrite the integrand in terms of
w = 3 - 2
p.
This is shown below.
Substitution:
Let
w = 3 - 2
p. Then
w' = -2, so
(-1/2)
dw =
dp.
The integral can therefore be rewritten as

sqrt(3 - 2
p)
dp =
w1/2 (-1/2)
dw =
-(1/3)
w3/2 +
C
Thus, substituting back for
w,

sqrt(3 - 2
p)
dp =
-(1/3) (3 - 2
p)
3/2 +
C
To evaluate the definite integral, we take this antiderivative,
evaluate it at the endpoints of the integral (-3 and 1),
and take the difference of the values. This gives
[ -(1/3) (3 - 2(1))3/2 ] - [ -(1/3) (3 - 2(-3))3/2 ] = 26/3.