Three consecutive odd numbers equals 117, what are the numbers

Brook states that the distance on the line is 4 units. caleb states that the whole line does not have a distance because it continues on forever. vivian states that the line is 6 units long. which distance did brook measure? which distance did vivian measure?

Which of the following is most likely the next step in the series? a3z, b6y, c9x, d12w, е15v, f18u

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).