Quadratics in the XC plane

by Kasey Nored

Our parent quadratic makes our
familiar parabola.

y = ax^{2 }+ bx + c where b and c equal zero

The manipulation of a, b, and c
shifts and dilates our parabola.

This write-up intends to explore
the xc plane where c serves
as y, for example to graph a point in the xc plane
(x, c) would be the coordinates. When we manipulate our quadratic ax^{2 }+
bx + c, using 1 for a and b, and solve for c we find
that c = –x^{2} – x

Our xc plane appears to merely flip and shift our parent
function, with our vertex at

When we change our original value
of c to 5, the red graph, or to .25, the black graph, our parabola dilates but
also moves our vertex.

For the equation our vertex lies at and the graph still has zeros at 0 and -1 which is reasonable

as our zeros are linked
with our values of a and b and here we have not changed our a and b values.

For the equation
our zeros remain and our vertex lies at

If we animate the denominator for
values between -10 and 10 we see the graph below.

You notice that the graph
continues to have the original zeros and dilates while changing the vertex.

Also of interest is the point
where c = 0 the graph is undefined.

Return to EMAT 6680

Return to my page