help with epsilon delta proof
I've read what's posted in the sticky section but I'm still a little confused on one part.
Here's my problem:
Find the limit L, then find a formula for delta>0 such that abs(f(x)-L)<epsilon whenever 0<abs(x-c)<delta for:
x is approaching 4
Here's my work:
The limit is 21
ok, now I get lost: abs(x-4)<epsilon/abs(2x+5)
I don't know what to do at this point. Can someone help
There was a similar problem on the pdf. under the sticky section (Example 4) involving (2x^2-x+3)=31
as they do the work they get < 17(epsilon/17), I can't see where they get 17, it seems like an arbitrary number.