Answer:
y2 = C1xe^(4x)
Step-by-step explanation:
Given that y1 = e^(4x) is a solution to the differential equation
y'' - 8y' + 16y = 0
We want to find the second solution y2 of the equation using the method of reduction of order.
Let
y2 = uy1
Because y2 is a solution to the differential equation, it satisfies
y2'' - 8y2' + 16y2 = 0
y2 = ue^(4x)
y2' = u'e^(4x) + 4ue^(4x)
y2'' = u''e^(4x) + 4u'e^(4x) + 4u'e^(4x) + 16ue^(4x)
= u''e^(4x) + 8u'e^(4x) + 16ue^(4x)
Using these,
y2'' - 8y2' + 16y2 =
[u''e^(4x) + 8u'e^(4x) + 16ue^(4x)] - 8[u'e^(4x) + 4ue^(4x)] + 16ue^(4x) = 0
u''e^(4x) = 0
Let w = u', then w' = u''
w'e^(4x) = 0
w' = 0
Integrating this, we have
w = C1
But w = u'
u' = C1
Integrating again, we have
u = C1x
But y2 = ue^(4x)
y2 = C1xe^(4x)
And this is the second solution
For c to be positive, and for b to be negative, m must be negative and n must be negative.
X^2 - bx + c = (x - m)(x - n).
c is the product of m and n. If both m and n are positive, c would be positive. However b is the sum of m and n, therefore to make b negative, both m and n must be negative to ensure that the product of m and n is positive
Answer: 
Step-by-step explanation:
This problem can be solved by the <u>Rule of Three</u>, which is a mathematical rule to find out an amount that is with another quantity given in the same relation as other two also known.
In this case, the 25 ounce drink represents the 
. So, if Mark drinks 5 ounces, this means he has 20 ounces left and we have to find the percent this represents:
------- 
-------- 
This is the percent of the drink Mark has left
Time taken by Max to cover the same distance walking at 4.2 km/h is 1.5 hours
<h3><u>Solution:</u></h3>
Given it takes Max 1.8 hours to walk home from work at a rate of 3.5km/h
We have to find time taken by Max to cover the same distance walking at 4.2 km/h
<em><u>The relation between speed and time is given as:</u></em>
<em><u>CASE 1:</u></em>
It takes Max 1.8 hours to walk home from work at a rate of 3.5km/h
Let us first find the distance covered
Time taken = 1.8 hours and speed = 3.5 km/hr
Hence distance covered is 6.3 km
<em><u>Now we have to find the time taken to cover same 6.3 km walking at 4.2 km\hr</u></em>
So time taken by Max to cover the same distance walking at 4.2 km/h is 1.5 hours
Approximately 68% of a normal distribution lies within one standard deviation of the mean, so this corresponds to students with scores between (57.5 - 6.5, 57.5 + 6.5) = (51, 64)
