Respuesta :

Answer:

[tex]\frac{a^3}{6}[/tex]

Step-by-step explanation:

First let's find the [tex]x[/tex]'s for which the curves form a enclosure.

We do this by finding when f and g intersect.

[tex]ax=x^2[/tex]

Subtract [tex]ax[/tex] on both sides:

[tex]0=x^2-ax[/tex]

Factor right hand side:

[tex]0=x(x-a)[/tex]

The product is zero when at least one of it's factors is zero.

So [tex]x=0[/tex] or [tex]x=a[/tex]

[tex]a[/tex] is positive and is greater than 0 so [tex]a[/tex] is the upper bound.

Also [tex]ax>x^2[/tex] when [tex]x[/tex] is between [tex]0 \text{and} a[/tex].

The integral we need to evaluate is:

[tex]\int_0^a (ax-x^2)dx[/tex]

[tex](\frac{ax^2}{2}-\frac{x^3}{3})_0^a[/tex]

Plug in limits:

[tex](\frac{aa^2}{2}-\frac{a^3}{3})- (\frac{a0^2}{2}-\frac{0^3}{3})[/tex]

[tex]\frac{a^3}{2}-\frac{a^3}{3}[/tex]

[tex]\frac{3a^3-2a^3}{6}[/tex]

[tex]\frac{a^3}{6}[/tex]