- Thread starter
- #1

#### NavalMonte

##### New member

- Feb 18, 2014

- 7

lim of arctan(-2x^3+3x-4x) as x approaches infinity

Any help would be appreciated

- Thread starter NavalMonte
- Start date

- Thread starter
- #1

- Feb 18, 2014

- 7

lim of arctan(-2x^3+3x-4x) as x approaches infinity

Any help would be appreciated

- Jan 30, 2012

- 2,513

- Thread starter
- #3

- Feb 18, 2014

- 7

I'm sorry, it's actually written as:

lim arctan($-2x^3+3x-4$)

x->∞

- Jan 30, 2012

- 2,513

- Thread starter
- #5

- Feb 18, 2014

- 7

I factored the largest factor of x from the polynomial and got:

lim $x^3$=∞

x->∞

and

lim $(-2+\dfrac{3}{x^2}-\dfrac{4}{x^2})$=-2

x->∞

Would that make the:

lim arctan (-2) =lim arctan($-2x^3+3x-4$)

x->∞................x->∞

Edit: I just realized that:

lim $-2x^3+3x-4$ = -∞

x->∞

Therefore,

lim arctan($-2x^3+3x-4$)= -$\dfrac{\pi}{2}$

x->∞

Would that be correct or am I totally off base?

Last edited:

- Jan 30, 2012

- 2,513

Edit: I just saw your edit, and it is correct. You may also see this discussion on StackExchange for a similar example.