The coefficient of x² in the polynomial x³-6x²+12x-8
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Answers
Answer:
the cofficient of X2 in the polynomial
Answer:ven that p(x) = x³ - 6x² + 12x - 8
So p(2) = (2)³ - 6.(2)² + 12.2 - 8 = 8 - 24 + 24 - 8 = 0
Therefore (x-2) is a factor of p(x)
Now p(x) = x³ - 6x² + 12x - 8
p(x) = x²(x-2) - 4x² + 12x - 8
p(x) = x²(x-2) -4x(x-2) + 4x - 8
p(x) = x²(x-2) -4x(x-2) + 4(x-2)
p(x) = (x-2) (x²-4x+4)
p(x) = (x-2) (x²-2x-2x+4)
p(x) = (x-2) [x(x-2)-2(x-2)]
p(x) = (x-2) (x-2) (x-2)
Another method : By using (x-y)³ = x³ - 3x²y + 3xy² - y³
x³ - 6x² + 12x - 8
= (x)³ - 3.(x)².2 + 3.x.(2)² - (2)³
= (x-2)³
Step-by-step explanation:
Given that p(x) = x
So p(2) = (2)³ - 6.(2)² + 12.2 - 8 = 8 - 24 + 24 - 8 = 0
Therefore (x-2) is a factor of p(x)
Now p(x) = x³ - 6x² + 12x - 8
p(x) = x²(x-2) - 4x² + 12x - 8
p(x) = x²(x-2) -4x(x-2) + 4x - 8
p(x) = x²(x-2) -4x(x-2) + 4(x-2)
p(x) = (x-2) (x²-4x+4)
p(x) = (x-2) (x²-2x-2x+4)
p(x) = (x-2) [x(x-2)-2(x-2)]
p(x) = (x-2) (x-2) (x-2)
Another method : By using (x-y)³ = x³ - 3x²y + 3xy² - y³
x³ - 6x² + 12x - 8
= (x)³ - 3.(x)².2 + 3.x.(2)² - (2)³
= (x-2)³
= (x-2