- #1
BOAS
- 552
- 19
Homework Statement
[/B]
Use integration by substitution to evaluate the integral,
[itex]I = \int^{x}_{x_{0}} (3 + 4t)^{\frac{5}{3}} dt[/itex]
Homework Equations
The Attempt at a Solution
I am confused by this question, and think that the limits on the integral might be a typo. Does it make sense for them to be [itex]x, x_{0}[/itex]? I think that the question means for them to be [itex]t, t_{0}[/itex] but I'm not sure that it isn't me not understanding something properly.
Ordinarily,
I would make the substitution [itex]u = 3 + 4t[/itex], and say that [itex]du = 4 dt[/itex].
[itex]I = \int^{3+4t}_{3+4t_{0}} (u)^{\frac{5}{3}} \frac{du}{4} = [ \frac{3}{5} \frac{u^{\frac{8}{3}}}{4}]^{3 + 4t}_{3+4t_{0}} = [ \frac{3}{5} \frac{(3+4t)^{\frac{8}{3}}}{4}]^{3 + 4t}_{3+4t_{0}}[/itex]
[itex]I = (\frac{3}{5} \frac{(3+4t)^{\frac{8}{3}}}{4}) - (\frac{3}{5} \frac{(3+4t_{0})^{\frac{8}{3}}}{4})[/itex]
It simplifies a bit further, but i'd really like confirmation that I have interpreted this question correctly.
Thanks.