Robin would have worked a total of 10 days!!! Hope this helps :) :) :)
Answer:
Step-by-step explanation:
Let the rate of boat in still water be b and the speed of the current be c
- Speed downstream = b + c
- Speed upstream = b - c
<u>We got equations for time:</u>
- 108/(b - c) = 3 ⇒ b - c = 36
- 108/(b + c) = 2 ⇒ b + c = 54
<u>Add up the equations:</u>
- b - c + b + c = 36 + 54
- 2b = 90
- b = 45 km/h
<u>Then finding the values of c</u>
Answer:
Step-by-step explanation:
a.) When you have the following equation 
To find the vertex you take the h value, change its sign (to positive in this case) and that will give you the x value. To find the y-value just take the z. This gives us (15,-100)
b.) The axis of symmetry is just the x value of the vertex which is 15
c.) I'm not too sure what this means but can tell you that it's concave up because there's no way x can be negative
d.)Because the a value is positive that means that the graph is concave up which means that it has a minimum. The minimum is just the y value of the vertex which is just -100
e.) I'm going to write this in interval notation. The domain is all the possible x values of the graph which is all real numbers or (-∞,∞). The range is all the possible y values. We know that the minimum is -100 which means all the possible y values are [-100,∞)
f.) This is obviously a parabola and because the graph is concave up and has a negative minimum there must be 2 x intercepts.
Answer:
I don't know
Step-by-step explanation:
could you screenshot your question or reword it. I don't know what you're asking. Sorry.
Answer:
−4y
Step-by-step explanation:
Since the directrix is vertical, use the equation of a parabola that opens up or down.
(x−h)2=4p(y−k)
Find the vertex.
The vertex (h, k) is halfway between the directrix and focus. Find the y coordinate of the vertex using the formula y = y coordinate of focus + directrix 2. The x coordinate will be the same as the x coordinate of the focus.
(3,−1+1
___
2)
Simplify the vertex.
Add − 1 and 1. (3,0/2) Divide 0 by 2. (3,0).
Find the distance from the focus to the vertex.
The distance from the focus to the vertex and from the vertex to the directrix is | p |. Subtract the y coordinate of the vertex from the y coordinate of the focus to find p. p = − 1 − 0 Subtract 0 from − 1 . p = − 1.
Substitute in the known values for the variables into the equation ( x − h ) 2 = 4 p (y − k). (x − 3) 2 = 4 (− 1) (y − 0).
Simplify.
(x − 3) 2= −4y
= −4y
