Answer:
y = (x - 3)² + 1
Step-by-step explanation:
the equation of a quadratic function in vertex form is
y = a(x - h)² + k
where (h, k ) are the coordinates of the vertex and a is a multiplier
here (h, k ) = (3, 1 ) , then
y = a(x - 3)² + 1
to find a substitute (1, 5 ) into the equatiuon
5 = a(1 - 3)² + 1 ( subtract 1 from both sides )
4 = a(- 2)² = 4a ( divide both sides by 4 )
1 = a
then equation of quadratic function is
y = (x - 3)² + 1
There is a formula for that;
Total time = (Worker 1 * Worker 2) / (Worker 1 + Worker 2)
Total time = (80 * 120) / (80 + 120)
Total time = 9,600 / 200
Total time = 48 minutes
The tail of the train starts one mile from the mouth of the tunnel and it must travel that distance plus the length of the tunnel in 3 minutes.
Let t = tunnel length
t + 1 = distance the tail must travel in 3 minutes.
3 minutes = 1/20 hr
(t+1) miles / 60 m/hr = 1/20 hr
t + 1 = 60/20
t+1 = 3
Subtract 1 from each side:
t = 2
The tunnel is 2 miles long.
