Stuck Again: Find the Correct Answer to ƒ(x)

[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?

 

[haruspex]

View attachment 102575 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?

Please post your working.

 

[SteamKing]

Also, please try to post your HW threads in the appropriate HW forum by topic.

 

[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.

 

[Hardikph]

OK get It.

 

[Ray Vickson]

View attachment 102575 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?

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

 

[Hardikph]

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

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