x+imaginary number as answer in quadratic equation

Question

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829

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AX^2 + BX + C = 0

What does it mean when the answer to a quadratic equation is a number +/- an imaginary number?

I know at least that it means: The number under the root sign is negative - but in the bigger picture what do I do with an answer like this?

Do I only use the the real number as an answer?

Guest Nov 30, 2014

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Best Answer

It means if you were to graph this on regular x y co-ordinates, the graph will not cross the x axis.

If you are asked to give a solution, use both the real and imaginary part as your solution in the form a + bi.

Quenton4 Nov 30, 2014

Quenton4 · Answer 1 · 2014-11-30T06:18:27

It means if you were to graph this on regular x y co-ordinates, the graph will not cross the x axis.

If you are asked to give a solution, use both the real and imaginary part as your solution in the form a + bi.

Melody · Answer 2 · 2014-12-01T12:49:24

Here are 2 examples of a quadratics with no real roots.

See how the parabolas lies entirely above or entirely below the x axis.