Problem 45

Question

Find the first partial derivatives of the following functions. $$F(u, v, w)=\frac{u}{v+w}$$

Step-by-Step Solution

Verified
Answer
Question: Find the first partial derivatives of the function F(u, v, w) = u / (v + w). Answer: The first partial derivatives of the function F(u, v, w) with respect to u, v, and w are: $$\frac{\partial F}{\partial u}=\frac{1}{v+w}$$ $$\frac{\partial F}{\partial v}=-\frac{u}{(v+w)^2}$$ $$\frac{\partial F}{\partial w}=-\frac{u}{(v+w)^2}$$
1Step 1: Calculate the Partial Derivative with respect to u
To find the partial derivative of the function F(u,v,w) with respect to u, we will treat v and w as constants and differentiate F with respect to u. The partial derivative with respect to u is denoted as: $$\frac{\partial F}{\partial u}$$ The function we have is: $$F(u, v, w)=\frac{u}{v+w}$$ Applying the derivative with respect to u, we have: $$\frac{\partial F}{\partial u}=\frac{1}{v+w}$$
2Step 2: Calculate the Partial Derivative with respect to v
Now, we will find the partial derivative of the function F(u,v,w) with respect to v by treating u and w as constants. The partial derivative with respect to v is denoted as: $$\frac{\partial F}{\partial v}$$ The function is still: $$F(u, v, w)=\frac{u}{v+w}$$ Applying the derivative with respect to v, we have: $$\frac{\partial F}{\partial v}=-\frac{u}{(v+w)^2}$$
3Step 3: Calculate the Partial Derivative with respect to w
Lastly, we will find the partial derivative of the function F(u,v,w) with respect to w, while treating u and v as constants. The partial derivative with respect to w is denoted as: $$\frac{\partial F}{\partial w}$$ The function remains: $$F(u, v, w)=\frac{u}{v+w}$$ Applying the derivative with respect to w, we have: $$\frac{\partial F}{\partial w}=-\frac{u}{(v+w)^2}$$
4Step 4: Final Result
The first partial derivatives of the function F(u, v, w) with respect to u, v, and w are as follows: $$\frac{\partial F}{\partial u}=\frac{1}{v+w}$$ $$\frac{\partial F}{\partial v}=-\frac{u}{(v+w)^2}$$ $$\frac{\partial F}{\partial w}=-\frac{u}{(v+w)^2}$$