Question

.

Answer 1

The formula for this
is
\[
\int_a^b \pi f^2(x)\, dx.
\]
Here, \(f(x) = \cos^{-1}(x),a=0,b=\frac\pi3\).
You must compute\[
\int_0^{\pi/3} \pi \frac1{\cos^2(x)}\,dx.
\]

Answer 2

What do they mean by "approximate with the calculator"?
- compute the integral with the calculator?
- use small cylinders to approximate the volume constructed by rotation?

Answer 3

Caution: \[\cos ^{-1}x \]
is the inverse cosine function. It is not equivalent to y=sec x.

If you want sec x, use this identity: sec x = 1/cos x

arccos x = The angle whose cosine is x

Answer 4

I got 5.441 thanks guys!

Answer 5

yeah.. I meant \((\cos x)^{-1}\). My bad ;) Thanks @mathmale