## Dodo1 2 years ago limit comupting limit using the limit law

1. Dodo1

$\lim_{x \rightarrow 1} \frac{ x^4+x^3-2x }{ }$

2. Dodo1

not working so Lim x^4+x^3-2x/x^5+2x-3 x->1

3. ZeHanz

Do you mean l'Hôpital's Rule by limit law? In that case take the derivative of both the numerator and the denominator and then take the limit as x goes to 1.

4. Dodo1

yes!

5. Dodo1

I thought I need to factorize first

6. ZeHanz

That can help sometimes, but factorising the denominator is difficult and l'H will crack it anyway...

7. Dodo1

Whats I`H?

8. Dodo1

I have to go meeting but I will back later. thanks,

9. ZeHanz

l'H = l'Hôpital's Rule

10. Dodo1

Do i plug numbers into the equation>?

11. LABurn

No, using l'Hôpital's Rule allows you to take the limit as x goes to 1 of the top and bottom separately.

12. ZeHanz

So, after differentiating separately yo now have this:$\lim_{x \rightarrow 1}\frac{ 4x^3+3x^2-2 }{ 5x^4+2 }$No 0/0 problem anymore, just set x=1 to see the result.

13. Dodo1

Ok thank you!

14. ZeHanz

YW!