if a ,b are the zeroes of thye polynomials p(x)= 2xsq - 3x +7 . then how will we find the value of a cube + b cube

Asked by vikramsingh | 16th May, 2013, 06:53: PM

Expert Answer:

p(x) = 2x^2 -3x+7
Hence, a+b = -(-3)/2 = 3/2
ab = 7/2
 
hence, a^3+b^3 = (a+b) (a^2-ab+b^2)
= (a+b) ((a+b)^2-3ab)
= 3/2 ((3/2)^2 - 3*7/2)
= -99/8

Answered by  | 16th May, 2013, 06:56: PM

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