The number of people newly infected on day t of a flu epidemic is f(t) = 13t^2 − t^3 (for 0 ≤ t ≤ 13). Find the instantaneous rate of change of this number on the following days. Day 5, Day 11

The revenue each season from tickets at the theme park is represented by t(c)=5x. the cost to pay the employees each season is represented by r(x)=(1.5)^x. examine the graph of the combined function for total profit and estimate the profit after four seasons

Adecibel is a logarithmic unit that can be used to measure the intensity of a sound. the function y = 10logx gives the intensity of a sound in decibels, where x is the ratio of the intensity of the sound to a reference intensity. the reference intensity is generally set at the threshold of hearing. use the graphing utility to graph the decibel function. a whisper has a sound intensity of 30 decibels. use your graph to you complete the following statement. the sound intensity of a whisper is times the reference intensity.

X+y=-4 x-y=2 use elimination with adding and subtraction