In [1]:
from sympy import init_printing; init_printing(use_latex='mathjax')
import sympy as sym

In [6]:
r, theta, k  = sym.symbols('r theta k')
r, theta, k


Out[6]:
$$\left ( r, \quad \theta, \quad k\right )$$

In [7]:
n = sym.Symbol('n', positive = True, integer=True)
n


Out[7]:
$$n$$

In [8]:
def lamb(n,k):
    return sym.Symbol('lambda_%s%s'%(n,k), positive = True)

In [10]:
lamb(0,k)


Out[10]:
$$\lambda_{0k}$$

In [11]:
f = 1 - r**2; f


Out[11]:
$$- r^{2} + 1$$

In [13]:
integrand = f * sym.besselj(n, lamb(n,k) * r) * sym.cos(n *theta) * r
integrand


Out[13]:
$$r \left(- r^{2} + 1\right) \cos{\left (n \theta \right )} J_{n}\left(\lambda_{nk} r\right)$$

In [14]:
ank = sym.Integral(integrand, (r, 0, 1), (theta, 0, 2*sym.pi))
ank


Out[14]:
$$\int_{0}^{2 \pi}\int_{0}^{1} r \left(- r^{2} + 1\right) \cos{\left (n \theta \right )} J_{n}\left(\lambda_{nk} r\right)\, dr\, d\theta$$

In [15]:
solution = ank.doit()
solution


Out[15]:
$$0$$

In [16]:
integ = lambda n: f * sym.besselj(n, lamb(n,k) * r) * sym.cos(n*theta) * r

In [17]:
integ(0)


Out[17]:
$$r \left(- r^{2} + 1\right) J_{0}\left(\lambda_{0k} r\right)$$

In [18]:
a0k = sym.Integral(integ(0), (r, 0, 1), (theta, 0, 2*sym.pi))
a0k


Out[18]:
$$\int_{0}^{2 \pi}\int_{0}^{1} r \left(- r^{2} + 1\right) J_{0}\left(\lambda_{0k} r\right)\, dr\, d\theta$$

In [19]:
a0k.doit()


Out[19]:
$$2 \pi \left(- \frac{2 J_{0}\left(\lambda_{0k}\right)}{\lambda_{0k}^{2}} + \frac{4 J_{1}\left(\lambda_{0k}\right)}{\lambda_{0k}^{3}}\right)$$

In [ ]: