please answer the question.The polynomial ax³+bx²+x-6 has(x+2) as a factor and leaves a remainder when divided by(x-2).Find a and b.
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=>a=0 and b=2.
Let p(x) =ax³+bx²+x-6.
By using factor theorem,(x-2) can be a factor of p(x) only when p(-2)=0.
p(-2)=a(-2)³+b(-2)²+(-2)-6=0.
=>-8a +4b-8=0.
Therefore,-2a+b =2...(1)
Also,when p(x) is divided by (x-2) the remainder is 4.
Therefore,p(2)=4.
=>a(2)³+b(2)²+2-6=4
=>8a+4b+2-6=4
=>8a+4b-4=4
=>8a+4b=4+4
=>8a+4b=8
=>2a+b=2...(2)
Adding equations (1) and (2),we get (-2a+b)+(2a+b)=2+2.
=>2b=4
=>b=2.
Putting b=2 in (1) ,we get
-2a +2=2
=>-2a=2-2
=>-2a=0
=>a=0.
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