The standard equation for a parabola that opens upward parallel to the y-axis is x2=4ay, where a = distance from the vertex to focus. Vertex is at origin(0,0)
4a=2
a=2/4
a=1/2 or 0.5
the coordinate of the focus is (0, 1/2)
the equation of the directrix is y=-1/2
Answer:
about 26 min
Step-by-step explanation:
Toni rows a boat 4.5 km/h upstream and then turns around and rows 5.5 km/h back downstream to her starting point
First we find the average speed
We add both speed and divide it by 2
Now we find the distance for round trip
given total time is 48 mins. convert mins into hours
48 mins = 48 divide by 60 = 0.8
average speed = 5 km/hr
Distance = speed * time = 5 * 0.8 = 4 km
distance covered both ways = 4 km
so 4 divide by 2 = 2 km each way
To find time taken for upstream = distance of each way / speed of upstream
time =
Now convert hours into minutes
0.44* 60= 26.4 minutes
Answer:
a) 79.6
b) 437.8
Step-by-step explanation:
First, you have to do 318.4/4 to find the rate she goes in the duration of an hour. The rate is 79.6, which means she travels at a rate of 79.6 kilometers per hour.
Then, you have to find the distance she takes to travel in 5.5 hours, so you have to do 5.5*79.6 which is 437.8.
So, Hannah travels 437.8 kilometers in 5.5 hours.
2 hours = 120 minutes. Divide 120 by 2, which is 40. So she has 40 minutes for each assignment