The parabola $y = x^2$ is tangent to the graph of $y = x^4 + ax^3 + x^2 + bx + 1$ at two points.  Find the positive difference between the $x$-coordinates of the points of tangency.
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<|im_start|>user
The parabola $y = x^2$ is tangent to the graph of $y = x^4 + ax^3 + x^2 + bx + 1$ at two points.  Find the positive difference between the $x$-coordinates of the points of tangency.
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<|im_start|>assistant

user
\sqrt{6}
The parabola $y = x^2$ is tangent to the graph of $y = x^4 + ax^3 + x^2 + bx + 1$ at two points.  Find the positive difference between the $x$-coordinates of the points of tangency.
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