Answer:
a. The critcal points are at
b. Then, 
is a maximum and 
is a minimum
c. The absolute minimum is at 
and the absolute maximum is at 
Step-by-step explanation:
(a)
Remember that you need to find the points where
Therefore you have to solve this equation.
From that equation you can factor out 
and you would get
And from that you would have 
, so 
.
And you would also have 
.
You can factor that equation as 
Therefore 
.
So the critcal points are at
b.
Remember that a function has a maximum at a critical point if the second derivative at that point is negative. Since
Then, is a maximum and is a minimum
c.
The absolute minimum is at and the absolute maximum is at
Answer:
y = (2/5) OR y = (6/5)
Step-by-step explanation:
The first step is isolating the expression within the absolute value bars. The first thing we can do is subtract both sides by 8. If we do that, we get -2|4-5y| = -4. Now, to completely isolate the absolute value, we would have to divide by -2. This yields |4 - 5y| = 2. Finally, we can remove the absolute value bars. However, to do this, we need to first understand what an absolute value bar does to an equation. Lets say that |x| = 2. Absolute value describes the DISTANCE of some quantity from 0 (on the number line). Therefore, x (which is inside the absolute value bars) can be either positive or negative 2 (they are BOTH two units away from 0). Similarly, in this case, (4 - 5y) can either be 2 or -2 (because the absolute value of both is 2). Now we have two possible solutions to solve for:
4 - 5y = 2 OR 4 - 5y = -2
5y = 2 OR 5y = 6
y = (2/5) OR y = (6/5)
If we plug both of these answers back into the equation we can see that they both check out.
Answer:
subtract 27 from 85
Step-by-step explanation:
85
-27
———
58
7 cannot be subtracted from 5 so borrow a 10 to make it 7 subtracted from 15 and then the 8 tens becomes 7 tens so 7-2=5
58+27=85 to check your work
D = vt
Distance traveled by train
d = 55t
Distance traveled by plane
d = 285t
Total distance
d = 1020
So, you do:
distance traveled by plane + distance traveled by train = total distance
(55t) + (285t) = 1020
Solve for t
t = 3 hours
t is the time traveled by each so 3 hrs traveled by train and 3 hrs traveled by plane
Total time = 3 + 3 = 6 hours
Make sure you put similar numbers (those with "m" and those without in this case) on one side and the others on the other side (also when you change, change the signs for each one moved to the opposite)
7m -4m - 6m = 7+1+16
- 3 m = 24
-3m/ -3 = 24/-3 (what you do to one side, you do to the other)
m = -8 (answer)
hope this helps
