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Numerical Ability
Quadratic Equations
a+b+c=0, then roots of ax^2+bx+c=0 is
1.imagenary 2.real 3.coincidental 4.zero
Read Solution (Total 1)
-
- roots are real.
x = [-b +/- sqrt(b^2 - 4ac)] / 2a ------------- [1]
Because
a+b+c = 0
b = -(a+c)
b^2 = (a+c)^2 = a^2+c^2 +2ac
b^2 -4ac = a^2+c^2-2ac = (a-c)^2 --------- [2]
solving [1] and [2], we get,
x = [a+c +/- (a-c)] / 2a
so
x = 1,
and
x = c/a ....... both are real roots - 13 years agoHelpfull: Yes(2) No(0)
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