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- 5 Apr 2008
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Hey guys...
So here's the question...
I was given that f(x) has an x^3 coefft of 1. The roots of f(x) are 0 , -1 , 2 and 5 ...
(i) write in factorised form and show that f(x) can be written as x^3 - 6x^2 + 3x + 10
So I factorised and got x^4 - 6x^3 + 3x^2 + 10x ... Then took out x as a factor to get the answer...
Here's the question... There were four factors... It was originally an x^4 graph... If I was going to sketch the graph then how does it work? As the fact there are 4 roots means that it wouldnt look like a cubic graph? Do I just ignore the x=0 root?
Edit: 0 doesn't give zero when substituted for x in the equation so that would mean it is not a root in the graph... But at the beginning if the question it said that 0 was a root... Now very confused :S
So here's the question...
I was given that f(x) has an x^3 coefft of 1. The roots of f(x) are 0 , -1 , 2 and 5 ...
(i) write in factorised form and show that f(x) can be written as x^3 - 6x^2 + 3x + 10
So I factorised and got x^4 - 6x^3 + 3x^2 + 10x ... Then took out x as a factor to get the answer...
Here's the question... There were four factors... It was originally an x^4 graph... If I was going to sketch the graph then how does it work? As the fact there are 4 roots means that it wouldnt look like a cubic graph? Do I just ignore the x=0 root?
Edit: 0 doesn't give zero when substituted for x in the equation so that would mean it is not a root in the graph... But at the beginning if the question it said that 0 was a root... Now very confused :S
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