Y=-.3x^2+3x
....
-2x+5.5y=19.5
5.5y=19.5+2x
y=(19.5+2x)/5.5
When the light touches the parabola y=y so
(19.5+2x)/5.5=-.3x^2+3x multiply both sides by 5.5
19.5+2x=-1.65x^2+16.5x add 1.65x^2 to both sides
1.65x^2+2x+19.5=16.5x subtract 16.5x from both sides
1.65x^2-14.5x+19.5=0
Using the quadratic equation for simplicity...
x=(14.5±√81.55)/3.3 we only need the lower point, or the smaller value of x
x≈1.657423 since:
y=(19.5+2x)/5.5
y≈4.15 units
Answer:
Elapsed time: 1 hour and 9 minutes
Step-by-step explanation:
7:41 - 8:41 = 1 hour
8:41 - 8:50 = 9 minutes
1 hour and 9 minutes
Hope that helps!
Answer: B
21x^2-17x+2
Step-by-step explanation:
