If x3+3x2-9x+c is of the form x-α2x-β then the positive value of c is ____
Here x=α isarepeatedrootoftheequation fx=0.Hence, x=α isalsoarootoftheequation f'x=0, i.e., 3x2+6x-9=0or x2+2x-3=0 or x+3x-1=0has the root α once which can be eitheer -3 or 1.If α=1, then fx=0 gives c-5=0 or c=5.If α=-3, then fx=0 gives -27+27+27+c=0∴ c=-27