Hi, Thank you for your help! Marcel
FindRoot works with polynomials and related symbolic expressions.
In[7]:= f[x_] = x^2; g[a_?NumberQ, b_?NumberQ] := NIntegrate[f[x], {x, a, b}] In[9]:= FindRoot[g[1, b] == 3, {b, 1}] Out[9]= {b -> 2.15443}
