Diff eq.

1. Apr 7, 2010

brusier

1. The problem statement, all variables and given/known data

I integrated dx/dt = x^2+(1/81)

2. Relevant equations

My result; 9(arctan(9x))= t+C needed to be solved for initial condition x(0)=-8
and fit into x(t) = format

3. The attempt at a solution

I cannot figure out why the computer is not accepting my solution:
arctan (9x)= (t-14.012)/9

2. Apr 7, 2010

PhysicsMark

Wouldn't that be:

$$x(t)=\frac{(tan(\frac{t-14.012}{9}))}{9}$$