Daniel O. answered 11/29/12
Math and Physics Tutor, with a math and physics degree
Are you looking for the area enclosed by y = x3 and y = x4?
To find the intercepts of the two curves, and thus the boundaries for the area enclosed, you need to find where the equations are equal (which you've done).
from x3 - x4 = 0 we can take out the common factor of x3 to get:
x3(1-x) = 0 (you can check this is correct by distributing the x3)
From here we can see that x = 0 and x = 1 will satisfy the equation, so those are our boundaries for the integral. Since y = x3 is greater than y = x4 between x = 0 and 1 (you can check this from a graph, even if you google this: y = x^3 and y = x^4), set up the integral to find the area enclosed like so:
Area = ∫01 x3 dx - ∫01 x4 dx
which integrates to: Area = [x4/4]01 - [x5/5]01
Which you can now solve by substituting in the values for x. If you need help on this last step, let me know.
Michael B.
Yup nice work... I think the OP was just asking about how to find the correct limits ("how do I find A&B"), which you provided - 0 and 1.
11/30/12