A car is traveling on a highway. The distance (in miles) from its destination and the time (in hours) is given by the equation d=420-65t. What is the practical meaning of the d-intercept? a. Initially the car is 355 miles from its destination. b. Initially the car is 420 miles from its destination. c. Initially the car is 65 miles from its destination. d.Initially the car is 485 miles from its destination.

Question

anonymous · Answer

Which number is a variable and which number is a constant in your equation?

anonymous · Answer

Variable?

anonymous · Answer

I'm confused

anonymous · Answer

65t is a variable as it will change as t changes.

anonymous · Answer

So D is the constant?

anonymous · Answer

No d is the solution and will change as t changes.

anonymous · Answer

Okay, now what? (Im sorry, thank you so much)

anonymous · Answer

Let t represent time in hours and D represent distance traveled. So of we are starting a trip the first value for t would be 0, because no time has passed. Thus when t = 0 this will represent where we are starting our trip from. distance wise.

anonymous · Answer

d=420-65(0) ?

anonymous · Answer

So d= what at our starting point?

anonymous · Answer

I have no clue! :(

anonymous · Answer

I don't completely understand what you are asking

calculusfunctions · Answer

An equation of a line is of the form y = mx + b, where m is the slope (the rate of change of y with respect to x) and b is the y-intercept (the initial value). You can now compare your equation to this one to figure it out. Hint: in your equation d is the same as y and t is the same as x.

anonymous · Answer

d=420-65t
y=mx+b
I still am confused

calculusfunctions · Answer

d =  420 - 65t
y =    b   + mx

If b is the initial value, then what is b in your equation? This is the initial distance from the destination.

anonymous · Answer

420?

calculusfunctions · Answer

You can also look at it another way. Initial distance d is when time t = 0. Thus you can substitute t = 0 in the equation and solve for d to determine the initial distance.

calculusfunctions · Answer

Yes! You got it! The initial distance is 420.

anonymous · Answer

Lol, it B? If it is i figured that out right before you sent it

calculusfunctions · Answer

Yes it's B

anonymous · Answer

Thank you!!!!!!!!!!

calculusfunctions · Answer

You're welcome.