Verify the identity
cos ( x + pi/2) = -sin x

Askyscraper is 396 meters tall. at a certain time of day, it casts a shadow that is 332 meters long.at what angle is the sun above the horizon at that time?

At the county fair, the baxter family bought 6 hot dogs and 4 juice drinks for $12.90. the farley family bought 3 hot dogs and 4 juice drinks for $8.55. find the price of a hot dog and the price of a juice drink.

Asmall book publisher knows that 26 books weigh 41 lbs. how much do 40 books weigh?