I have absolutely no idea how to solve these type of problems. My teacher gave a lecture about this subject two days ago, and I took a look at this stickied thread, but I'm still stuck. :s
In exercises 1–8, numerically and graphically determine a δ corresponding to (a) ε = 0.1 and (b) ε = 0.05. Graph the function in the ε − δ window [x-range is (a − δ, a δ) and y-range is (L − ε, L + ε)] to verify that your choice works.
limx→0 (x^2 + 1) = 1
In exercises 9–20, symbolically find δ in terms of ε.
15.limx→1 (x^2 + x − 2)/(x − 1) = 3
52.A fiberglass company ships its glass as spherical marbles. If the volume of each marble must be within ε of π/6, how close does the radius need to be to 1/2?