Consider a function f(x1,...,xn)of nvariables. How many different partial derivatives of order rdoes fpossess?

Short Answer

Expert verified

The different partial derivatives of order rthat fpossess arelocalid="1648374000028" n+r-1!(r-1)!n!.

Step by step solution

01

Step 1. State the proposition.

The proposition used here is:

There are n+r-1r-1distinctive non negative integer valued vectors localid="1648373873954" x1,x2,.......,xnsatisfying the equationx1+x2+......+xn=n.

02

Step 1. Find the number of partial derivatives.

The given function f(x1,...,xn)consists of nvariables.

We have to find the partial derivatives of order rpossessed by f.

This means we have to non negative integer valued vectors of x1,x2,.......,xn

Therefore, from the above proposition, the different partial derivatives of order rpossessed by f is given by

n+r-1!(r-1)!n!.

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 Vaia!

One App. One Place for Learning.

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

Get started for free

Most popular questions from this chapter

Consider the grid of points shown at the top of the next column. Suppose that, starting at the point labelled A, you can go one step up or one step to the right at each move. This procedure is continued until the point labelled B is reached. How many different paths from A to B are possible? Hint: Note that to reach B from A, you must take 4steps to the right and 3steps upward.

The game of bridge is played by 4players, each of who is dealt 13cards. How many bridge deals are possible?

Consider a tournament of ncontestants in which the outcome is an ordering of these contestants, with ties allowed. That is, the outcome partitions the players into groups, with the first group consisting of the players who tied for first place, the next group being those who tied for the next-best position, and so on. Let localid="1648231792067" N(n)denote the number of different possible outcomes. For instance, localid="1648231796484" N(2)=3, since, in a tournament with localid="1648231802600" 2contestants, player localid="1648231807229" 1could be uniquely first, player localid="1648231812796" 2could be uniquely first, or they could tie for first.

(a) List all the possible outcomes when n=3.

(b) With localid="1648231819245" N(0)defined to equal localid="1648231826690" 1, argue without any computations, that localid="1648281124813" N(n)=i=1nniNn-i

Hint: How many outcomes are there in which localid="1648231837145" iplayers tie for last place?

(c) Show that the formula of part (b) is equivalent to the following:

localid="1648285265701" N(n)=i=1n-1niNi

(d) Use the recursion to find N(3) and N(4).

For years, telephone area codes in the United States and Canada consisted of a sequence of three digits. The first digit was an integer between 2 and 9, the second digit was either 0 or 1, and the third digit was any integer from 1 to 9. How many area codes were possible? How many area codes starting with a 4 were possible

Expandx1+2x2+3x34.

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free