Q. 3 A3.7( 3 Votes )

# If x = 1 is a root of ax^{2} + bx + c = 0, a 0, a, b, c R, prove that a + b + c = O.

Answer :

As x = 1 is a root of ax^{2} + bx + c = 0 hence x = 1 will satisfy the equation ax^{2} + bx + c = 0

Put x = 1 in ax^{2} + bx + c = 0

⇒ a × (1)^{2} + b × (1) + c = 0

⇒ a + b + c = 0

Hence proved

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