For the polynomial f(x)=2x^3-9x^2+11x-20 as
x---- -infinity, f(x)---- +infinity
True or False?

Question

For the polynomial f(x)=2x^3-9x^2+11x-20 as
x----> -infinity, f(x)----> +infinity 
True or False?

johnweldon1993 · Answer

Well first, quick thing

If I have a HUGE number...and I add a small number to it... does it make much of a difference?

sharkfinsoup · Answer

no

johnweldon1993 · Answer

Good...so then for your problem all we really need to focus on is the term that is being raised to the 3rd power...since that is so much bigger than the other terms being added to it

SO

As $\large x \rightarrow -\infty$ of $\large 2x^3$    what does it come out to?

johnweldon1993 · Answer

Also meaning...if we take a negative number and raise it the the third power...will it come out negative? or positive?

sharkfinsoup · Answer

negative

johnweldon1993 · Answer

Exactly, so for your question...is the answer true or false?

sharkfinsoup · Answer

It's false right? Because the whole thing, f(x), should be equal to negative infinity

johnweldon1993 · Answer

Correct

sharkfinsoup · Answer

Ok thank you so much

johnweldon1993 · Answer

No problem!