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I'm trying to find and so far cant find what is

vector1.x * vector2.y - vector2.x * vector1.y

When I'm googling most results is about vector multiplication, but in the articles I haven't found this formula yet.

Bruice
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    Do you mean vector1.x * vector.y - vector.x * vector1.y? If so, this is a cross product. – eyeballfrog Jun 17 '21 at 11:59
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    This is horribly unclear. What sort of objects are vector1.x and vector.y etc.. What sort of multiplication are you doing? Are you perhaps trying to multiply components of the vectors? If so... what is causing you trouble here? That is... for instance if vector1 happens to be $(4,7)$ for instance, that is with $x$ coordinate $4$ and $y$ coordinate $7$, and vector happens to be $(10,20)$ (these numbers picked arbitrarily just so you can see them show up again later)... then vector1.x * vector.y - vector.x * vector.y would simply be $4\cdot 20 - 10\cdot 20$ – JMoravitz Jun 17 '21 at 12:01
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    You ask "What is"... are you asking for how to evaluate it? Or are you asking for some physical interpretation of this? Are you sure you have no typos? Would you consider using math notation rather than programming notation to make it clearer? For instance $v_xu_y - u_xu_y$ specifying that $v$ is a vector $v=(v_x,v_y)$ etc...? – JMoravitz Jun 17 '21 at 12:03
  • @eyeballfrog Yes, indexes got lost on editing, sorry. I've looked through https://en.wikipedia.org/wiki/Cross_product ,but there formulas always involves angles, so I decided it's something else – Bruice Jun 17 '21 at 12:07
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    Does this answer your question? Why determinant of a 2 by 2 matrix is the area of a parallelogram? – JMoravitz Jun 17 '21 at 12:07
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    @Bruice If you look at this section you'll see that this is the z-component of the cross product of the two vectors. – eyeballfrog Jun 17 '21 at 12:09
  • @eyeballfrog thanks! Can you write an answer so I can accept it? – Bruice Jun 17 '21 at 12:15

1 Answers1

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This is the $z$-component of the cross product of the two vectors.

eyeballfrog
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