2.Find the equation of the line in the graph and mathematically model the scenario using function notation where cost is a function of number of minutes.

Question

anonymous · Answer

attachment

campbell_st · Answer

ok... the let line will be in the form 

Cost(C) = m*time(t) + b

so you need to find the y intercept... which is b... 

where does the line cut or start on the vertical axis...?

anonymous · Answer

B

anonymous · Answer

@campbell_st  I'm not to sure what you mean and @Lainey06 there arent chocies haha

campbell_st · Answer

ok... so look at the graph as where does it start... on the vertical axis...?

campbell_st · Answer

or what is the cost when time is zero...?

anonymous · Answer

On the graph the vertical axis starts somewhere @LilliBelle

anonymous · Answer

The cost when it's zero is 20

campbell_st · Answer

thats great so the line as a function is 

c(t) = mt + 20

now pick t points to find the slope 

I'd choose (0, 20) and (400, 40)

you need to find the slope 


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so can you calculate the slope m....by using the diagram...?

anonymous · Answer

So I have to divide 400 by 20?

campbell_st · Answer

nope other way   20 divided by  400

anonymous · Answer

Wow I feel dumb now haha Okay so it would be 20

campbell_st · Answer

yes the equation ends up as 

C(t) = 0.05t + 20

so its saying the cost of the plan is $20 and then 5 cents for every minute of call time... 

the slope   0.05   means you pay 5 cents per minute or $0.05 per minute for calls... 

hope it helps

anonymous · Answer

Thank you very much!!!!!!!