How to calculate following differential equation.
 y''(x)=-y^3-0.05y'+7.5cos(x)  [x=0 to 100, y(0)=0, y'(0)=0]

Step 1:
Input equation like this.

Step 2:
Press "Set Condition" button and input like this.

Step 3:
Press  button.

And Mathbrain begins calculation and draws graph at the same time like this.


If you use Mathematica to calculate, you need to type following script.


NDSolve[{y''[x] == -y[x]^3-0.05 y'[x]+7.5 Cos[x],y'[0] == 0,y[0] == 0},y[x],{x,0,100},MaxSteps->10000]


{{y[x] -> InterpolatingFunction[{0., 100.}, <>][x]}}


Plot[y[x] /. %,{x,0,100}]

And Mathematica begins calculation and draws graph. You need to wait to see graph until calculation finishes.