Proving Vector OA + OB + OC Perpendicularity in Regular Tetrahedrons

In summary, a regular tetrahedron has four equilateral faces and each interior angle is 60 degrees. By finding the coordinates of the vertices, it can be proven that the sum of the three vectors (OA, OB, and OC) is perpendicular to the base plane ABC.
  • #1
jaejoon89
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"The vertices of a regular tetrahedron are OABC. Prove that vector OA + OB + OC is perpendicular to plane ABC."

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No idea how to do this. Please help.
 
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  • #2
Each face of a regular tetrahedron is an equilateral triangle. There is one face at the bottom and three other faces making four faces in all. Each interior angle of an equilateral triangle is 60 degrees.

Can you use this information to find the coordinates of the vertices of your tetrahedron? Once you have them, then you can add your three vectors together and see that their sum is perpendicular to the base.
 

1. What is a vector proof?

A vector proof is a mathematical method used to demonstrate the validity of a statement or theorem involving vectors. It involves using algebraic and geometric properties of vectors to show that the given statement is true.

2. How do you write a vector proof?

To write a vector proof, you need to clearly state the given statement or theorem, and then break it down into smaller parts. You can then use algebraic and geometric properties of vectors to manipulate the equations and show that each part is equal, thus proving the statement to be true.

3. What are some properties of vectors used in vector proofs?

Some common properties used in vector proofs include the commutative, associative, and distributive properties of vector addition and scalar multiplication, as well as the properties of vector dot and cross products.

4. Can vector proofs be used to prove non-geometric statements?

Yes, vector proofs can be used to prove non-geometric statements as long as the statements involve vectors and their properties. For example, vector proofs can be used to prove equations involving forces in physics or displacement in engineering.

5. Are there any common mistakes to avoid when writing a vector proof?

One common mistake to avoid when writing a vector proof is to assume that the given statement is true without properly proving it. It is important to break down the statement into smaller parts and show the logical steps used to prove each part. Additionally, it is important to be familiar with the properties of vectors and use them correctly in the proof.

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