I solved it, thank you anyways.
If you are interested how it was solved:
Has basis of dimension 2 if p,q are continous in an neigborhood of x=0.
Thus, there exists two linearly independent solutions that span the set. One is given as sin(x^2). Let the other linearly independent solution be y.
Then we compute the Wronskian,
But at x=0 the Wronskian is zero.
Thus, there does not exist a linearly independant solution with sin(x^2), a contradiction.