SOLUTION: The length of a car's skid mark in feet is given by L=0.042s2−0.199s+0.264,where sis the car's speed in miles per hour. If the length of a skid mark is110feet, find the speed

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: The length of a car's skid mark in feet is given by L=0.042s2−0.199s+0.264,where sis the car's speed in miles per hour. If the length of a skid mark is110feet, find the speed      Log On


   

Question 987006: The length of a car's skid mark in feet is given by L=0.042s2−0.199s+0.264,where sis the car's speed in miles per hour. If the length of a skid mark is110feet, find the speed in miles per hour the car was traveling.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
The length of a car's skid mark in feet is given by L=0.042s2−0.199s+0.264, where
s is the car's speed in miles per hour.
If the length of a skid mark is 110feet, find the speed in miles per hour the car was traveling.
:
0.042s^2 − 0.199s + 0.264 = 110
0.042s^2 − 0.199s + 0.264 - 110 = 0
0.042s^2 − 0.199s - 109.736 = 0
Using the quadratic formula: x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
where in this equation a = .042; b = -.199; c = -109.736
I got a positive solution of:
s = 53.5391 mph
:
See if that is what you get.