another problem i worked half way on and stuck on

ODE is dx/dt = x^(3/4)

i need to find values for constans a > 0 and b or which x(t) = (at)^b is a solution of the ODE or t>0. Is this function also a solution for t<0?

ok, so here goes my crazy method in doing this..

x'(t) = ba(at)^(b-1)

put this into the ODE:

ba(at)^(b-1) = ((at)^b)^3/4

now what?.. no initial conditions are given. how do they expect us to find a and b =S and..... determine t? =| that looks crazy.. how you obtain a,b,t from that equation

thank you