Raphael K. answered • 09/17/21
I genuinely love teaching Calculus and have for 10+ years.
A solar water heater costs about $6240 to install (after rebates). A traditional gas water heater costs about $850, and costs about $320 per year to run. The average annual cost to run the solar water heater is about $75. A) Create total cost functions for each of the water heaters as a function of the number of years that it is used, and graph these functions on the same set of axes. B) How many years would you need to use a solar water heater in order for the total cost to become less than the total cost of the gas water heater?
Solar Cost(n) = 6240 + 75n
Gas Cost(n) = 850 + 320n
Find the number of years that the costs will be equal:
6240 + 75n = 850 + 320n
5390 = 245n
22 = n
After 22 years the cost for the solar heater will be less, assuming it still works.
Raphael K.
Draw one line to represent the solar It has a y intercept of 6240 and a slope of 75 Cnn be graphed in desmos using y = 75x + 6240 Draw another line to represent the gas It has a y intercept of 850 and a slope of 320 Can be graphed using y = 320x + 850 The point of intersection of the 2 lines will be on the graph at (22, 7890) Any questions?09/17/21
Ximena M.
How can I graph it?09/17/21