SOLUTION: The fuel efficiency F for a particular car is given by F(x) = –0.018 x2 + 1.548 x + 4.2 What is the fuel efficiency if the car’s speed is 70 mph? i got 24.36, is this correct?

Algebra ->  Functions -> SOLUTION: The fuel efficiency F for a particular car is given by F(x) = –0.018 x2 + 1.548 x + 4.2 What is the fuel efficiency if the car’s speed is 70 mph? i got 24.36, is this correct?       Log On


   

Question 747887: The fuel efficiency F for a particular car is given by F(x) = –0.018 x2 + 1.548 x + 4.2
What is the fuel efficiency if the car’s speed is 70 mph? i got 24.36, is this correct?
What speed will yield the maximum fuel efficiency?
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
The fuel efficiency F for a particular car is given by F(x) = –0.018 x2 + 1.548 x + 4.2
What is the fuel efficiency if the car’s speed is 70 mph? i got 24.36, is this correct?
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F(x) = –0.018 x2 + 1.548 x + 4.2
F(70) = -0.018*70^2 + 1.548*70 + 4.2
= 24.36
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Looks right.
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The best mileage is at 43 mi/hr, apx 37.5 mi/gallon (if mpg is the units)
Don't be in the left lane at 43 mi/hr, tho.