if x minus 1 and x minus 2 is a factor of PX barabar x ki power 4 minus 5 x cube + 4 x square + a x + B then find the value of a and b
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ans: a=8 , b=-8
if (x-1)(x-2) are factors of P(x), then P(1) = 0 AND P(2) = 0.
So, 1-5+4+a+b=0 (putting x as 1)
and 2⁴-5(2³)+4(2²)+a(2)+b=0
you now have two equations and two variables.
we can see from the first equation that a+b =0
and on simplification of 2nd equation , we get:
16-40+16+2a+b=0
2a+b=8
and,
a+b=0
b= -a
substitute in the other equation, 2a+(-a)=8
a=8
b=-8
if (x-1)(x-2) are factors of P(x), then P(1) = 0 AND P(2) = 0.
So, 1-5+4+a+b=0 (putting x as 1)
and 2⁴-5(2³)+4(2²)+a(2)+b=0
you now have two equations and two variables.
we can see from the first equation that a+b =0
and on simplification of 2nd equation , we get:
16-40+16+2a+b=0
2a+b=8
and,
a+b=0
b= -a
substitute in the other equation, 2a+(-a)=8
a=8
b=-8
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