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Quadratic eqns-sum and product of roots 
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Quadratic eqns-sum and product of roots
by JiaGengMaths on Thu Apr 19, 2012 8:33 am
The equation 2x^2+px+24=0(where p<0), has roots A and B where A-B=4. Evaluate A and B and hence, or otherwise, find the value of p.
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Re: Quadratic eqns-sum and product of roots 
by maggiemagnet on Fri Apr 20, 2012 1:27 pm
JiaGengMaths wrote:The equation 2x^2+px+24=0(where p<0), has roots A and B where A-B=4. Evaluate A and B and hence, or otherwise, find the value of p.
Divide through by 2. Then use the fact that, for roots A and B and equation x^2 + bx + c = 0, A + B = b and A*B = c.
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