# factors Watch

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find the co ordinates where the graph of

y=2x^3 + 3x^2 - 4x +1

cuts the x axis??????

y=2x^3 + 3x^2 - 4x +1

cuts the x axis??????

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#2

find the co ordinates where the graph of

y=2x^3 + 3x^2 - 4x +1

--

Factor theorem

F(x) = 2x^3 + 3x^2 - 4x +1

When F(1) = 2 + 3 - 4 + 1 = 2 therfore (x - 1) is not a factor

F(-1) = -2 + 3 + 4 + 1 = -2

Factor theorem doesn't work...

What question is this btw, c2 or c3?

you can only use the factor theorem for factors of 1 as 1 is the integer at the end.

y=2x^3 + 3x^2 - 4x +1

--

Factor theorem

F(x) = 2x^3 + 3x^2 - 4x +1

When F(1) = 2 + 3 - 4 + 1 = 2 therfore (x - 1) is not a factor

F(-1) = -2 + 3 + 4 + 1 = -2

Factor theorem doesn't work...

What question is this btw, c2 or c3?

you can only use the factor theorem for factors of 1 as 1 is the integer at the end.

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#3

(0,1) isn't a solution because that's not on the x-axis.

also if your factorisation were correct, the curve would be y = x^3 + 3x^2 + 3x + 1 by the binomial expansion.

try searching for factors by the factor theorum.

also if your factorisation were correct, the curve would be y = x^3 + 3x^2 + 3x + 1 by the binomial expansion.

try searching for factors by the factor theorum.

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#5

Can't be a c2 question asthe factor theorem doesnt even work.

1 & -1 are both unsuccessful

you sure the question is right?

Could always try numerical methods

1 & -1 are both unsuccessful

you sure the question is right?

Could always try numerical methods

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#6

(Original post by

find the co ordinates where the graph of

y=2x^3 + 3x^2 - 4x +1

cuts the x axis??????

**sarah12345**)find the co ordinates where the graph of

y=2x^3 + 3x^2 - 4x +1

cuts the x axis??????

f(1/2)=2/8+3/4-2+1=0

factor theorem gives (2x-1) is a factor

2x^3+3x^2-4x+1=(2x-1)(x^2+2x-1)

f cuts x-axis at x=1/2

x=-2+-rt(4+4)/2=-1+-rt(2)

0

(Original post by

f(x)=2x^3+3x^2-4x+1

f(1/2)=2/8+3/4-2+1=0

factor theorem gives (2x-1) is a factor

2x^3+3x^2-4x+1=(2x-1)(x^2+2x-1)

f cuts x-axis at x=1/2

x=-2+-rt(4+4)/2=-1+-rt(2)

**evariste**)f(x)=2x^3+3x^2-4x+1

f(1/2)=2/8+3/4-2+1=0

factor theorem gives (2x-1) is a factor

2x^3+3x^2-4x+1=(2x-1)(x^2+2x-1)

f cuts x-axis at x=1/2

x=-2+-rt(4+4)/2=-1+-rt(2)

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#8

(Original post by

how did you get f(1/2) do you just guess?

**sarah12345**)how did you get f(1/2) do you just guess?

0

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