The depth of a river at a certain point is modeled by the function W(t) = { 17/2 - 3/2 cos( (t x pi)/6) for 0< or equal to t < or equal to 6; 10 - 1/5 (t - 6)^2 for 6< t < or equal to 10, where W (t) is measured in feet and time t is measured in hours.
A) find W’(8). Using correct units, explain the meaning of W’(8) in the context of the problem.
B) the graph of W is concave down for 3< or equal to t < or equal to 3.5. Use the line tangent to graph of W at t = 3 to show W(3.5). < or equal to 9
C) find lim as x approaches 2 for (W(t) - t^3 + 1/4)/(t - 2)

The variable in a relation who’s value depends on the value of the independent variable is called what?

Someone answer asap for ! a discount store’s prices are 25% lower than department store prices. the function c(x) = 0.75x can be used to determine the cost c, in dollars, of an item, where x is the department store price, in dollars. if the item has not sold in one month, the discount store takes an additional 20% off the discounted price and an additional $5 off the total purchase. the function d(y) = 0.80y - 5 can be used to find d, the cost, in dollars, of an item that has not been sold for a month, where y is the discount store price, in dollars. create a function d(c(x)) that represents the final price of an item when a costumer buys an item that has been in the discount store for a month. d(c(x)) =

What is the greatest number of parts of a circle that can be formed by cutting the circle with 7 straight cuts? (note: the parts do not have to be equal in size)