Find the remainder when the polynomial x 8 1 + x 4 9 + x 2 5 + x 9 + x is divided by x 3 − x 2 .
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let P ( x ) = x 3 − x 2 , F ( x ) = x 8 1 + x 4 9 + x 2 5 + x 9 + x and r ( x ) = r e m a i n d e r than F ( x ) = P ( x ) Q ( x ) + r ( x ) for some polynomial Q(x) F ( x ) − r ( x ) = P ( x ) Q ( x ) and hence P ( x ) ∣ F ( x ) − r ( x ) that also means that if P ( a 1 ) = P ( a 2 ) = 0 , F ( a 1 ) − r ( a 1 ) = F ( a 2 ) − r ( a 2 ) = 0 we see that the roots of P ( x ) = 0 , x = ( 1 , 0 ) hence F ( 1 ) − r ( 1 ) = 0 ⟶ r ( 1 ) = 5 and F ( 0 ) − r ( 0 ) = 0 ⟶ r ( 0 ) = 0 since zero is a root of r(x) and the its maximum degree is 2, it can be written as r ( x ) = ( x + 0 ) ( z x + n ) from 1 of the eqs, r ( 1 ) = 5 = 1 ( z + n ) − − > z + n = 5 we see that the only choice from the option satisfying this is 4 x 2 + x
Substitute 1 into both equations. Observe the remainder is 5. Therefore the only answer is 4xsqaured +x
short and sweet solution !!! :-))
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Iff we substitute x = 1 in the equation that you have typed in the fifth line of your solution we get 5 = a + b + c i.e sum of coefficients of the remainder is 5 Please point if wrong.
at x=1 the GE=5 and also 4x^2+x=5 at x=1 simple!
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