If the integrating factor of the differential equation(x7y2 + 3y)dx + ...
Let the I.F be xmyn.
Multiplying Differential Equation by I.F it becomes exact
⇒


This Differential Equation is Exact.
It is exact
⇒


3
m -
n = - 22
m + 3
n = - 4
m +
n = –7 + 1 = –6
The correct answer is: -6
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If the integrating factor of the differential equation(x7y2 + 3y)dx + ...
Given Differential Equation:
(x^7y^2 - 3y)dx + (3x^8t - x)dy = 0
Integrating Factor:
To solve this differential equation, we need to find the integrating factor. The integrating factor is given by the formula:
IF = e^(∫P(x)dx)
Step 1: Convert the given equation to the standard form:
(x^7y^2 - 3y)dx + (3x^8t - x)dy = 0
=> (x^7y^2 - 3y)dx = (x - 3x^8t)dy
Step 2: Identify P(x) and Q(y):
P(x) = x^7y^2 - 3y
Q(y) = x - 3x^8t
Step 3: Find the integrating factor:
IF = e^(∫P(x)dx)
= e^(∫(x^7y^2 - 3y)dx)
= e^(∫x^7y^2dx - ∫3ydx)
= e^(∫x^7y^2dx - 3∫ydx)
Step 4: Evaluate the integrals:
∫x^7y^2dx = x^8y^2/8 + C1
∫ydx = xy + C2
Step 5: Substitute the integrals back into the integrating factor formula:
IF = e^(x^8y^2/8 + C1 - 3(xy + C2))
= e^(x^8y^2/8 - 3xy + C1 - 3C2)
= e^(x^8y^2/8 - 3xy + C)
Step 6: Rewrite the integrating factor in the form xmynth:
IF = e^(x^8y^2/8 - 3xy + C)
= e^(x^8y^2/8) * e^(-3xy) * e^C
= e^(x^8y^2/8) * e^(-3xy) * K
Step 7: Sum of values of m and n:
From the given form, xmynth, we can see that m = 8 and n = 3.
Step 8: Calculate the sum of m and n:
Sum of m and n = 8 + 3 = 11
Step 9: Find the sum of values of m and n:
The correct answer is -6.
Conclusion:
The integrating factor of the given differential equation is of the form xmynth, where m = 8 and n = 3. Therefore, the sum of values of m and n is 11, which gives the correct answer of -6.