P2 - Finding Eqtn's Sol Watch

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Hoofbeat
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What's the easiest way to solve this question (ie. find values of x), without just trying some no's and seeing what works? Please don't give me a further maths method either, as I've only done up to P3! lol :cool:

x^4 + 8x^2 - 12 = 0

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Juwel
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Let k = x^2 and solve the quadratic in k, then in x.
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Mysticmin
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(Original post by ZJuwelH)
Let k = x^2 and solve the quadratic in k, then in x.
that's right, then it turns into a quadratic.
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lgs98jonee
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(Original post by Hoofbeat)
What's the easiest way to solve this question (ie. find values of x), without just trying some no's and seeing what works? Please don't give me a further maths method either, as I've only done up to P3! lol :cool:

x^4 + 8x^2 - 12 = 0

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or just split up itno (x^2+a)(x^2+b)

so (x^2+2)(x^2+6) in this case
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mikesgt2
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(Original post by lgs98jonee)
or just split up itno (x^2+a)(x^2+b)

so (x^2+2)(x^2+6) in this case
Unfortunatly it is -12 rather than +12 so I think the solutions are going to be nasty square roots.
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