# Stuck Again : --> 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?

## Answers and Replies

haruspex
Science Advisor
Homework Helper
Gold Member
2020 Award
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
Staff Emeritus
Science Advisor
Homework Helper
Also, please try to post your HW threads in the appropriate HW forum by topic.

symbolipoint
Homework Helper
Education Advisor
Gold Member
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.

OK get It.

Ray Vickson
Science Advisor
Homework Helper
Dearly Missed
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.

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).