easy quadratic question (1 Viewer)

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Find the roots of the quadratic 2(z^2) + z + 2 and hence express 2(z^2) + z + 2 as a product of two linear factors.

It's meant to be an easy question but I just don't know how to do it. Please help!

 

[Sober]

Find the roots of the quadratic 2(z^2) + z + 2 and hence express 2(z^2) + z + 2 as a product of two linear factors.

It's meant to be an easy question but I just don't know how to do it. Please help!

Using the quadratic formula:

z = [-1 ± √(1-16)] / 4

= -¼ ± i(√15 / 4)

Thus:

2(z^2) + z + 2 = (z + ¼ + i[√15 / 4])(z + ¼ - i[√15 / 4])

 

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Wow, that was a quick reply

Thanks a lot, sober!

 

[alexvincent]

This question involves imaginary numbers. Extension 1 students aren't required to knew/learn about complex numbers are they? It only comes into the syllabus in the ext2 course.

 

[Riviet]

Extension 1 students aren't required to knew/learn about complex numbers are they? It only comes into the syllabus in the ext2 course.

That is correct, imaginary numbers are only in the extension 2 course.