Answer:
A
Step-by-step explanation:
its the first one
Answer: The speed of the boat in still water is 6.5 mph.
The speed of the current is 2.5 mph
Step-by-step explanation:
Let x represent the speed of the boat in still water.
Let y represent the speed of the current.
A boat going upstream on The River averages 4 mph. Assuming it travelled against the current while going upstream, its total speed would be (x - y) mph. It means that
x - y = 4- - - - - - - - - - - -1
Going downstream, the boat averages 9 mph. Assuming it travelled with the current while going upstream, its total speed would be (x + y) mph. It means that
x + y = 9- - - - - - - - - - - -2
Adding both equations, it becomes
2x = 13
x = 13/2
x = 6.5 mph
Substituting x = 6.5 into equation 1, it becomes
6.5 - y = 4
y = 6.5 - 4
y = 2.5 mph
Let's solve ~
If it passes through x, then let's find x when y = 0
So, required values of x are 3 and -2
Now, let's differentiate the equation to get slope slope for tangent ~
Now, plug in the values of x to find slopes of tangents
and
We know, tangent are normal are perpendicular. so let's find out slopes of normals m1' and m2'
and
Now, write the equations of normals using point slope form :
Normal 1 : passing through (3 , 0), and slope = -1/5
and
Normal 2 : passing through (-2 , 0), and slope = 1/5
That's all for Aunty ~ hope it helps !
Step-by-step explanation:
1) Divide both sides by 0.72.
2) Simplify- 5.76/0.72 to 8.
Therefor the answer is m = -8.