Consider the cluster of galaxies CL0024+17 located in Pisces and assume
an axially-symmetric mass distribution for the cluster which can be
described by the following parametric lens model with isothermal profile:
kappa(theta) = 0.5 * theta_e / theta and abs(gamma) = kappa, where
Einstein radius of the cluster is theta_E = 0.5 arcmin.

a) Plot the radial mass profile kappa and reduced shear g as a function
of angular separation theta from the cluster center in the range:
0.5 arcmin < theta < 3 arcmin.

b) Plot the distorted images of four circular sources with radius
R = 0.1 arcmin, located at x-axis and with the following angular
separations from the cluster center: 0.8, 1.0, 1.4 and 1.8 arcmin.
Assume that shear direction is along x-axis.