Q3 of 83 Page 76

If x = 1 is a root of ax2 + bx + c = 0, a 0, a, b, c R, prove that a + b + c = O.

As x = 1 is a root of ax2 + bx + c = 0 hence x = 1 will satisfy the equation ax2 + bx + c = 0


Put x = 1 in ax2 + bx + c = 0


⇒ a × (1)2 + b × (1) + c = 0


⇒ a + b + c = 0


Hence proved


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