# Revision history [back]

### Access integration constant

Hi,

Consider the following code:

x = var('x')

f = function('f')(x)

sol = desolve(diff(f,x), [f,x])

print "sol =", sol

solve(sol, _C)

For which I'm getting NameError: name '_C' is not defined. What would be the right way to set the integration constant after the resolution of the differential equation?

Thanks!