Which pair of equations can be used to verify the rectangular form, z = a + bi, and the polar form of a complex number are equivalent? a = sin(θ) and b = cos(θ)
a = cos(θ) and b = sin(θ)
a = rsin(θ) and b = rcos(θ)
a = rcos(θ) and b = rsin(θ)

Which of the following is not a subset of {1,2,3}?

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)) =

With number 11 ( show how you got the answer)