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It being given that 1 is a zero of the polynomial (7x-x-6), find itsother zeros.XAMPLE 10 |
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Answer» 1 is one of the zeros of the given polynomial 7x - x^3 - 6=0 when x = 1 , 7x - x^3 - 6 = 0 => x - 1 is a factor of the polynomial 7x -x^3 - 6=0 Factorize the polynomial so that x - 1 becomes one of its factors now, 7x - x^3 - 6 = - (x^3 - 7x + 6) = - (x^3 - x^2 + x^2 - x - 6x + 6) = - {(x*3 - x^2) + (x^2 - x) - 6(x - 1)} = - {x^2(x - 1) + x(x - 1) - 6(x - 1)} = - (x - 1)(x^2 + x - 6) - (x -1){ x^2 + 3x - 2x - 6} = - (x - 1){(x^2 + 3x) - (2x + 6)} = - (x - 1){x(x + 3) - 2(x + 3)} = - (x - 1)(x + 3)(x - 2) The other factors of the polynomial are (x + 3) and (x - 2). The other roots of the polynomial is -3 and 2. |
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