Stuck Again : -->

1. Jun 28, 2016

Hardikph

I was doin' some coursera quiz. It asked this question :
Let ƒ(x) = (x2 - x - 42) / x-7
find as x → 7.
Now I approach x from both sides and it get me 2 different answer.
So which one is correct:
13 or 14?

2. Jun 28, 2016

haruspex

3. Jun 28, 2016

SteamKing

Staff Emeritus

4. Jun 28, 2016

symbolipoint

Note that simplifying f will give the LINE y=x+6, and the FUNCTION is undefined for x=7. The limit at x=7 is that missing point. You just need to set x=7 for y=x+6.

5. Jun 28, 2016

Hardikph

OK get It.

6. Jun 28, 2016

Ray Vickson

The function is not $f(x) = \frac{x^2-x-42}{x} -7$, as you wrote.

7. Jul 6, 2016

Hardikph

Yes it must be like ƒ(x) = (x2 - x - 42) / (x-7).