Question

Let 𝑒 = 𝑓(π‘₯, 𝑦) = (𝑒^π‘₯)𝑠𝑒𝑛(3𝑦). Check if 9((πœ•^2) u / πœ•(π‘₯^2)) +((πœ•^2) 𝑒 / πœ•(𝑦^2)) = 0

262

likes
1311 views

Answer to a math question Let 𝑒 = 𝑓(π‘₯, 𝑦) = (𝑒^π‘₯)𝑠𝑒𝑛(3𝑦). Check if 9((πœ•^2) u / πœ•(π‘₯^2)) +((πœ•^2) 𝑒 / πœ•(𝑦^2)) = 0

Expert avatar
Frederik
4.6
96 Answers
To check if \(9\frac{\partial^2 u}{\partial x^2} + \frac{\partial^2 u}{\partial y^2} = 0\), we need to calculate the second partial derivatives of u with respect to x and y, and then verify if the equation holds. First, let's find the first and second partial derivatives of \(u = f(x, y) = e^x \sin(3y)\): 1. First partial derivatives: \(\frac{\partial u}{\partial x} = \frac{\partial}{\partial x}(e^x \sin(3y))\) Using the product rule, we have: \(\frac{\partial}{\partial x}(e^x \sin(3y)) = e^x \sin(3y) + e^x \frac{\partial}{\partial x}(\sin(3y))\) \(\frac{\partial u}{\partial x} = e^x \sin(3y) + 0\) \(\frac{\partial u}{\partial x} = e^x \sin(3y)\) 2. Now, let's find the second partial derivative with respect to x: \(\frac{\partial^2 u}{\partial x^2} = \frac{\partial}{\partial x}(e^x \sin(3y))\) Using the product rule again: \(\frac{\partial}{\partial x}(e^x \sin(3y)) = e^x \sin(3y) + e^x \frac{\partial}{\partial x}(\sin(3y))\) The second term, \(\frac{\partial}{\partial x}(\sin(3y))\), is 0 since the derivative of sin(3y) with respect to x is 0. So, \(\frac{\partial^2 u}{\partial x^2} = e^x \sin(3y)\) 3. Next, let's find the first partial derivative with respect to y: \(\frac{\partial u}{\partial y} = \frac{\partial}{\partial y}(e^x \sin(3y))\) Using the chain rule, we have: \(\frac{\partial}{\partial y}(e^x \sin(3y)) = e^x \cdot 3\cos(3y)\) \(\frac{\partial u}{\partial y} = 3e^x\cos(3y)\) 4. Finally, let's find the second partial derivative with respect to y: \(\frac{\partial^2 u}{\partial y^2} = \frac{\partial}{\partial y}(3e^x\cos(3y))\) Using the chain rule again: \(\frac{\partial}{\partial y}(3e^x\cos(3y)) = 3e^x\cdot(-3\sin(3y)) = -9e^x\sin(3y)\) Now, we can plug these results into the equation \(9\frac{\partial^2 u}{\partial x^2} + \frac{\partial^2 u}{\partial y^2} = 0\): \(9(e^x \sin(3y)) + (-9e^x\sin(3y)) = 0\) \(9e^x \sin(3y) - 9e^x\sin(3y) = 0\) The equation simplifies to: \(0 = 0\) So, the equation \(9\frac{\partial^2 u}{\partial x^2} + \frac{\partial^2 u}{\partial y^2} = 0\) holds, and it is satisfied.

Frequently asked questions (FAQs)
What is the derivative of the cosine function?
+
What is the formula for finding the area of a triangle, and how is it calculated?
+
What is the value of log(x) / ln(x)?
+
New questions in Mathematics
Find two natural numbers whose sum is 230 and their difference is 10. Set up the system and solve it.
5(4x+3)=75
what is 3% of 105?
a bank finds that the balances in its savings accounts are normally distributed with a mean of $500 and a standard deviation off of $40. What is the probability that a randomly selected account has a balance of more than $400?
2. Juan is flying a piscucha. He is releasing the thread, having his hand at the height of the throat, which is 1.68 meters from the ground, if the thread forms an angle of elevation of 50Β°, at what height is the piscucha at the moment that Juan has released 58 meters of the thread?
If eight basketball teams participate in a tournament, find the number of different ways that first, second, and third places can be decided assuming that no ties are allowed.
The function g:Q→Q is a ring homomorphism such that g(3)=3 and g(5)=5. What are the values of g(8) and g(9)?
What is the r.p.m. required to drill a 13/16" hole in mild steel if the cutting speed is 100 feet per minute?
4. Show that if n is any integer, then n^2 3n 5 is an odd integer
Desarrolla (2x)(3y + 2x)5
If you randomly selected one person from the 900 subjects in this study, what is the probability that the person exhibits the minimum BMI?
In a grocery store, when you take out 3 peppers and 4 carrots, there are 26 peppers and 46 carrots left. How many peppers and carrots were there initially?
RaΓΊl, Gilberto and Arturo are playing golf; The probabilities of winning for each one are as follows: (RaΓΊl wins) = 20% (Gilberto wins) = 0.05% (Arturo wins) = ΒΎ%. Perform operations and order events from least to most probable.
The price per night of a suite at the Baglioni Hotel in Venice is 1896 euros, VAT included. The VAT in Italy is 25%. The hotel gets a return of 10% out of the price VAT included. a) What is the amount of VAT paid by the hotel for one
Let X be a discrete random variable such that E(X)=3 and V(X)=5. Let π‘Œ = 2𝑋^2 βˆ’ 3𝑋. Determine E(Y).
Let G be the center of gravity of triangle ABC. We draw through A a parallel to BC on which we take a point D so that DGβŠ₯BG. If the area of the quadrilateral AGBD is equal to s, show that ACΒ·BDβ‰₯2Β·s.
solve R the following equation 4 x squared - 35 - 9 over x squared is equal to 0
if y=1/w^2 yw=2-x; find dy/dx
The perimeter of a rectangular rug is 42 feet. The width is 9 feet. What is the length?
A triangle is cut by a line s parallel to the base in such a way that it divides the side of the triangle into parts in the ratio of 2 : 3. Find the other side of the triangle if it is known that the line s divides it into parts whose length is 5 cm.