Calculate the value of the forms \(\omega_{1}=d x_{2} \wedge d x_{3}, \omega_{2}=x_{1} d x_{3} \wedge d x_{2}\), and \(\omega_{3}=d x_{3} \wedge d r^{2}\left(r^{2}=x_{1}^{2}+x_{2}^{2}+x_{3}^{2}\right)\), on the pair of vectors \(\xi=(1,1,1), \eta=(1,2,3)\) at the point \(\mathbf{x}=(2,0,0)\).

Short Answer

Expert verified
Answer: The values of the evaluated differential forms at point (2, 0, 0) are as follows: Λ1 = 2 Λ2 = -6 Λ3 = 4

Step by step solution

01

Calculate the wedge product

We have three given forms, \(\omega_1\), \(\omega_2\), and \(\omega_3\). First, we need to calculate the wedge product for each form. For \(\omega_1\), we have \(d x_{2} \wedge d x_{3}\). The wedge product is linear, and anti-commutative, so we have: \(\omega_{1}=d x_{2} \wedge d x_{3} = -d x_{3} \wedge d x_{2}\) For \(\omega_2\), we have \(x_{1} d x_{3} \wedge d x_{2}\). The wedge product is linear and anti-commutative, so once again we have: \(\omega_{2} = x_{1} d x_{3} \wedge d x_{2} = x_{1} (- d x_{2} \wedge d x_{3}) = - x_{1} d x_{2} \wedge d x_{3}\) Lastly, for \(\omega_3\), we have \(d x_{3} \wedge d r^{2}\). First, we must compute the differential \(d r^{2}\). Given that \(r^{2} = x_{1}^{2} + x_{2}^{2} + x_{3}^{2}\), we have: \(dr^{2} = 2 x_{1} dx_{1} + 2 x_{2} dx_{2} + 2 x_{3} dx_{3}\) Now, we can calculate the wedge product: \(\omega_{3}=d x_{3} \wedge d r^{2} = d x_{3} \wedge (2 x_{1} dx_{1} + 2 x_{2} dx_{2} + 2 x_{3} dx_{3})\)
02

Plug the given vectors and point into each form

Now that we have the computed wedge products for each form, we need to plug in the given vectors and point \(\mathbf{x}\) to each form. For \(\omega_{1}\) we have: \(\omega_{1}(\xi, \eta) = -d x_{3}(\xi) \wedge d x_{2}(\eta)\) For \(\omega_{2}\) we have: \(\omega_{2}(\xi, \eta) = - x_{1} d x_{2}(\xi) \wedge d x_{3}(\eta)\) For \(\omega_{3}\) we have: \(\omega_{3}(\xi, \eta) = d x_{3}(\xi) \wedge (2 x_{1} dx_{1}(\eta) + 2 x_{2} dx_{2}(\eta) + 2 x_{3} dx_{3}(\eta))\)
03

Evaluate expressions at the given point

Lastly, we need to evaluate the expressions at the point \(\mathbf{x} = (2, 0, 0)\). For \(\omega_{1}\): \(\omega_{1} = -d x_{3}(\xi) \wedge d x_{2}(\eta) = -1 \wedge 2 = 2\) For \(\omega_{2}\): \(\omega_{2} = - x_{1} d x_{2}(\xi) \wedge d x_{3}(\eta) = -2 (1 \wedge 3) = -6\) For \(\omega_{3}\): \(\omega_{3} = d x_{3}(\xi) \wedge (2 x_{1} dx_{1}(\eta) + 2 x_{2} dx_{2}(\eta) + 2 x_{3} dx_{3}(\eta)) = 1 \wedge (4 + 0 + 0) = 4\) So we have the values of the forms: \(\omega_{1}(\xi, \eta) = 2\) \(\omega_{2}(\xi, \eta) = -6\) \(\omega_{3}(\xi, \eta) = 4\)

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

Study anywhere. Anytime. Across all devices.

Sign-up for free