1

I have an assignment where we are suposed to find the angle between two complex vectors and we have been given the formula angle to try to work out the problem and were told by the prof. that he got it from wikipedia. I went to the page to try to figure out what that fancy R meant and I found this insteadangle and still no clue as to the R or Re meant, any help?

Morg Man
  • 43
  • 2
    The links to the images have gone stale. If you still have the images, could you please upload them to the stack.imgur image hosting that is associated with Stack Exchange, to keep them available? – Daniel Fischer Feb 12 '16 at 00:50

2 Answers2

5

That's the "real part" of a complex number.
For example, $\Re(2+3i)=2$. (Also written as: $\operatorname{Re}(2+3i)=2$.)

There is also a symbol for the "imaginary part."
For example, $\Im(2+3i)=3$. (Also written as: $\operatorname{Im}(2+3i)=3$.)

In general, if $z=a+bi$, then $\Re(z)=a$ and $\Im(z)=b$.

Akiva Weinberger
  • 23,062
1

This means the real part. For example, if $z = a+bi$, then Re$(z) = a$

Euler....IS_ALIVE
  • 4,707