Can YOU solve this question? (1 Viewer)

[Render777]

From maths in focus, Challenge excercise 2, question 12.


The cost of running a car at an average speed of v km/h is given by c = 150 + v^2/80 cents per hour. Find the average speed, to the nearest km/h, at which the cost of a 500km trip is a minimum.



I've been stuck for like 2 hours, I can't seem to solve it.

 

[lolwot]

http://community.boredofstudies.org/showthread.php?t=148499&p=2999592&viewfull=1#post2999592

 

[Focus is Key]

Ugh I remember this question from last year. You need to know all the formulas from time etc. I remember no-one in the class could get it and the teacher had to show us all how.