What equations are associated with the different types of variation? How do you know which to use?

In the diagram, the ratio of ab to ae is (1/2) . what is the ratio of the length of to the length of ?

Which of the following is the result of expanding the series

What is the range of the function? f(x)=-2|x+1|? a. all real numbers. b. all real numbers less than or equal to 0. c. all real numbers less than or equal to 1. d. all real numbers greater than or equal to 1