Question

Use the graph below which shows the profit y in thousands of dollars of a company in a given year t where t represents the number of years since 1980 find the linear function y where y depends on t the number of years since 1980 Y=_

Answer 1

First we need to find the slope by using two points

(15,190)=(t1,y1)

(25,170)=(t2,y2)

`m=(y_2-y_1)/(t_2-t_1)=(170-190)/(25-15)=(-20)/(10)=-2`

Then we calculate the y-intercept

`190=-2(15)+b`

we isolate the b

`b=190+30=220`

The equation is

`y=-2t+220`