Good Evening
When I ask sage:
var('phi r')
phi1 = 0
phi2 = 2*pi
r1 = 3
r2 = 5
fpolar = - sqrt(-2*r^2*cos(phi)^2+25)
BI = fpolar
BI= integral(BI, (phi,phi1,phi2))
BI= integral(BI, (r,r1,r2))
BI
the result is:
-integrate(integrate(sqrt(-2*r^2*cos(phi)^2 + 25), phi, 0, 2*pi), r, 3,
5)
I've found no way to make sage integrate the expresion. It repeats my input and iam not given any new information.
When i try
BI.n()
i get
ValueError: Integrand has wrong number of parameters
Same Problem with indefinite Integrals
in:
BI = fpolar
BI= integral(BI, phi)
BI
out:
-integrate(sqrt(-2*r^2*cos(phi)^2 + 25), phi)
Why? what do I need to do to get the desired output?
