/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q. 2 FB The derivative when two variable... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

The derivative when two variables are held fixed: Let

\begin{equation}f(x, y, z)=x^2 y^3 \sqrt{z}\end{equation}

. Find the rate of change of f in the (positive) z-direction when the values of x and y are constant. Find the rate of change of f in the (positive) y direction when the values of x and z are constant. Find the rate of change of f in the (positive) x direction when the values of y and z are constant.

Short Answer

Expert verified

The rate of change of f in the (positive) z-direction when the values of x and y are constant is

\begin{equation}\frac{\partial f}{\partial z}=\frac{x^2 y^3}{2\sqrt{z}}\end{equation}

The rate of change of f in the (positive) y direction when the values of x and z are constant is

\begin{equation}\frac{\partial f}{\partial y} =3x^2 y^2 \sqrt{z}\end{equation}

The rate of change of f in the (positive) x direction when the values of y and z are constant is

\begin{equation}\frac{\partial f}{\partial x} =2x y^3 \sqrt{z}\end{equation}

Step by step solution

01

Step 1. Given Information

\begin{equation}f(x, y, z)=x^2 y^3 \sqrt{z}\end{equation}

02

Step 2. Calculation

The Rate of change of f in the z-direction(positive) when the values of x and y are constant is partially differentiating the given function f with respect to z i.e

\begin{equation} \frac{\partial f}{\partial z}=x^{2}y^{^{3}}\frac{\partial }{\partial z}\left ( z^{1/2} \right )\end{equation}

\begin{equation}\frac{\partial f}{\partial z}=x^{2}y^{^{3}}\left ( 1/2 \right )\left ( z^{1/2-1} \right )\end{equation}

\begin{equation} \frac{\partial f}{\partial z}=\frac{x^{2}y{^{3}}}{2}\left ( z^{-1/2} \right)\end{equation}

\begin{equation}\frac{\partial f}{\partial z}=\frac{x^{2}y{^{3}}}{2\sqrt{z}}\end{equation}

The Rate of change of f in the y-direction(positive) when the values of x and z are constant is partially differentiating the given function f with respect to y i.e

\begin{equation}\frac{\partial f}{\partial y}=x^{^{2}}\left ( \frac{\partial }{\partial y}y^{3}\right)\sqrt{z}\end{equation}

\begin{equation}\frac{\partial f}{\partial y}=x^{^{2}}(3*(y^{^{3-1}})\sqrt{z}\end{equation}

\begin{equation}\frac{\partial f}{\partial y}=x^{^{2}}(3y^{^{2}})\sqrt{z}\end{equation}

\begin{equation}\frac{\partial f}{\partial y}=3x^{^{2}}y^{^{2}}\sqrt{z}\end{equation}

The Rate of change of f in the x-direction(positive) when the values of y and z are constant is partially differentiating the given function f with respect to x i.e

\begin{equation}\frac{\partial f}{\partial x}=\left ( \frac{\partial }{\partial x}(x^{2}) \right )y^{^{3}}\sqrt{z}\end{equation}

\begin{equation}\frac{\partial f}{\partial x}=(2x^{2-1})y^{^{3}}\sqrt{z}\end{equation}

\begin{equation}\frac{\partial f}{\partial x}=2xy^{^{3}}\sqrt{z}\end{equation}

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Study anywhere. Anytime. Across all devices.