Prelim Polynomials Question (1 Viewer)

Ambility · Sep 24, 2015

I am 90% sure this question is wrong, but I wanted to post it here just in case I'm wrong.

$$Show that a polynomial with leading term $-x^3$ and a double root at $x=1$ has another root at point where $x>1.$
This is from Margaret Grove's Preliminary Maths in Focus 3 Unit textbook - 12.5 Q20.

I believe the function $-x^3+3x-2$ is in itself a contradiction what the question asks you to show?

integral95 · Sep 24, 2015

Ambility said:
I am 90% sure this question is wrong, but I wanted to post it here just in case I'm wrong.

$$Show that a polynomial with leading term $-x^3$ and a double root at $x=1$ has another root at point where $x>1.$
This is from Margaret Grove's Preliminary Maths in Focus 3 Unit textbook - 12.5 Q20.

I believe the function $-x^3+3x-2$ is in itself a contradiction what the question asks you to show?

yup you're right, the question probably needs more information since the polynomial is in the form

$-(x-\beta)(x-1)^2$

and there's nothing in the question that would restrict beta to be greater than 1

and now we know why Math in focus is unreliable

leehuan · Sep 24, 2015

LOL. Nice one Grove. Contradicts $-\left( x-a \right) { \left( x-1 \right) }^{ 2 }\forall a<1\quad$

Prelim Polynomials Question (1 Viewer)

Ambility

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integral95

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leehuan

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