Partial Derivative
A grocer's daily profit from the sale of two brands of cat food is
P(x,y)=(x−70)(50−7x+8y)+(y−60)(86+7x−4y)
cents, where x is the price per can of the first brand and y is the price per can of the second, each in cents. Currently the first brand sells for 84 cents per can and the second for 75 cents per can.
a) Use marginal analysis to estimate the change in the daily profit that will result if the grocer raises the price of the first brand by one cent, but keeps the price of the second brand unchanged.

Question

Partial Derivative
  A grocer's daily profit from the sale of two brands of cat food is
P(x,y)=(x−70)(50−7x+8y)+(y−60)(86+7x−4y)
cents, where x is the price per can of the first brand and y is the price per can of the second, each in cents. Currently the first brand sells for 84 cents per can and the second for 75 cents per can.
a) Use marginal analysis to estimate the change in the daily profit that will result if the grocer raises the price of the first brand by one cent, but keeps the price of the second brand unchanged.