help with quadratic function (1 Viewer)

BadBoo

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Hey guys, can you please help me with this question:
If a and B are the roots of the quadratic equation 2x^2+4x-5=0, evaluate a^3+b^3.

Thanks!
 

RealiseNothing

what is that?It is Cowpea
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Alternative way:

Multiply both sides by 'x':



Since A and B are roots:





Solve simultaneously:







Now we want to find

Using sums and products of roots:







Also note that:



Sub this into the other expression we got:





Let's hope I didn't typo this time.....
 
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