What is cos(180)? , i really need it for a quiz prep sheet!

Jordan rides his bike 6 7/15 miles every day to deliver newspapers and to go to and from school. if his ride to and from school is 4 3/10 miles, how many miles is the trip to deliver newspapers? 1 1/3 1 1/6 2 1/6 2 4/5

To find the extreme values of a function f(x.y) on a curve x-x(t), y y(t), treat f as a function of the single variable t and use the chain rule to find where df/dt is zero. in any other single-variable case, the extreme values of f are then found among the values at the critical points (points where df/dt is zero or fails to exist), and endpoints of the parameter domain. find the absolute maximum and minimum values of the following function on the given curves. use the parametric equations x=2cos t, y 2 sin t functions: curves: i) the semicircle x4,y20 i) the quarter circle x2+y-4, x20, y20 b, g(x,y)=xy

The jewelry store is having a sale. necklaces that were regularly priced at $23.50 are on sale for $18.80. what is the percentage of decrease in the price of necklaces?