please explain

Given the graph of f (I) above, find the following limits. To enter co in your answer field, . When you are in text entry mode (when your answer field has just one line), type the word infinity with a lower case i. . When you are in equation editor entry mode (when your answer field has multiple lines with the equation symbol menu bar), choose the symbol oo to enter co. You can switch entry modes by clicking on the button with the upper case Greek letter _ next to the answer field. (a) lim f (x) = I+-00 (b) lim f (I) = I-+00