If two of the zeros of the cubic polynomial ax3 + bx2 + cx + d are each equal to zero, then the third zero is

Given,


ax3 + bx2 + cx + d


By Putting x = 0


0 + d = 0


d = 0


ax3 + bx2 + cx + d = 0


x(ax2 + bx + c) = 0


Put x = 0


c = 0


ax2 + bx = 0


x(ax + b) = 0


Hence,


x = – b/a

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