Is the difference between two rational numbers always rational number

Using d, e, and f as values on a triangle and d being 60 degrees, what is the value of e and f if d is 60 degrees? also, what do you notice about the values of e and f?

"you know, playing tennis is healthier than watching a tennis match on television," katya remarked to her couch potato brother. in this sentence, healthier is a/an a. superlative. b. comparative. c. positive form. d. adverb.

Which of the following is the true for f(x) = 5cos