Using factor theorem, factorize each of the following polynomial:

3x3-x2-3x+1

Let, f (x) = 3x3-x2-3x+1

The factors of the constant term


The factor of the coefficient of x3 is 3. Hence, possible rational roots of f (x) are:



We have,


f (1) = 3 (1)3 – (1)2 – 3 (1) + 1


= 3 – 1 – 3 + 1


= 0


So, (x – 1) is a factor of f (x)


Let us now divide


f (x) = 3x3-x2-3x+1 by (x - 1) to get the other factors of f (x)


Using long division method, we get


3x3-x2-3x+1 = (x – 1) (3x2 + 2x – 1)


Now,


3x2 + 2x - 1 = 3x2 + 3x – x – 1


= 3x (x + 1) – 1 (x + 1)


= (3x – 1) (x + 1)


Hence, 3x3-x2-3x+1 = (x – 1) (x + 1) (3x – 1)


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