Please modify the code below to answer question (a). Thank you!

(a) Consider a rod of length 19.90 units that is made of some metal (let's call it Pachium), which has another element (Kocharium) dissolved in it. The initial concentration of Kocharium is given as C(x,t=0)=0.5(1+cos(2x/20)), and its diffusivity is =1. Modifying the python program we wrote in the class for solving a similar problem, calculate and plot the concentration of Kocharium near the center of the rod (between x=8 and x=10 ) at t=0.000,t=1.000, and t=2.000. Use x=0.1 and t=0.001. You can use either Runge-Kutta or predictor-corrector for the time evolution