Use the double bar graph below to answer the following question. Which city decreased in population between 1990 and 2000?

Philadelphia
Dallas
Phoenix
San Diego

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

Emily is entering a bicycle race for charity. her mother pledges $0.90 for every 0.75 mile she bikes. if emily bikes 18 miles, how much will her mother donate?

Acyclist bike x distance at 10 miles per hour .and returns over the same path at 8 miles per hour.what is the cyclist average rate for the round trip in miles per hour ?