Answer: \(x=1\) and \(x=-\frac52\).
The curve is
\(y=x^3+\dfrac32x^2-2x+1.\)
Differentiate:
\(\dfrac{\mathrm dy}{\mathrm dx}=3x^2+3x-2.\)
At \(x=0\), the gradient of the tangent is
\(-2.\)
Therefore the gradient of the normal is the negative reciprocal:
\(\dfrac12.\)
When \(x=0\), the point on the curve is
\((0,1).\)
So the equation of the normal is
\(y-1=\dfrac12x,\)
or
\(y=1+\dfrac12x.\)
To find where this normal cuts the curve again, solve
\(x^3+\dfrac32x^2-2x+1=1+\dfrac12x.\)
Subtract the right-hand side:
\(x^3+\dfrac32x^2-\dfrac52x=0.\)
Multiplying by \(2\),
\(2x^3+3x^2-5x=0.\)
Factorise:
\(x(2x^2+3x-5)=0.\)
Then
\(2x^2+3x-5=(2x+5)(x-1).\)
So the intersections have
\(x=0,\quad x=-\dfrac52,\quad x=1.\)
The value \(x=0\) is the original point of contact, so the two other \(x\)-coordinates are
\(x=1\quad\text{and}\quad x=-\dfrac52.\)