Couldn’t train nn for solving 2nd order ODE

I am trying to solve 2nd order ODE which is

y”+100y=0, y(0)=0, y'(0)=10 on [0, 1] interval

using neural network. Here is the code: https://colab.research.google.com/gist/rprtr258/717c07b72f2263ca0dc401c83e9179e5/2nd-order-ode.ipynb#scrollTo=zeub0DBC9pkr

But I have two problems:

1. I guess tf recompiles(retraces) some function during learning which slows learning proccess significantly. Putting whole learning process into function doesn’t help.
2. NN doesn’t fit at all. I guess it might be because of gradient size on last layer or something. Anyway it is difficult to test during 1.

Any help with problem 1 and maybe problem 2 will be appreciated.