A curve has gradient function $\displaystyle k(2x-1)^{2} $

and passes through the origin and the point (1,2). Find the equation if the curve.

I am not sure, how would I work out the value of k?

$\displaystyle k \int (2x-1)^{2} $ =

$\displaystyle k \frac{1}{6} (2x-1)^{3} + c $

Is this correct? If so from here, how would I proceed?

I have two unknowns, so unable to put the values of x and y given.