A-1-1-i-B-2-i-2-C-1-3i-1-i-are-given-find-angle-between-AB-and-AC-

Question Number 58154 by behi83417@gmail.com last updated on 18/Apr/19

A (1, 1 + i), B (\sqrt{2} + i, 2), C (1 - 3 i, 1 - i)

are given .

find angle between : AB and AC .

Answered by MJS last updated on 18/Apr/19

if i = \sqrt{- 1} then A, B, C \in R^{4} with coordinates

A = (\begin{matrix} 1 \\ 0 \\ 1 \\ 1 \end{matrix}) B = (\begin{matrix} \sqrt{2} \\ 1 \\ 2 \\ 0 \end{matrix}) C = (\begin{matrix} 1 \\ - 3 \\ 1 \\ - 1 \end{matrix})

and I {don}^{'} t know how to calculate angles,

especially of skew lines in R^{4}

Commented by behi83417@gmail.com last updated on 18/Apr/19

d e a r M J S s i r! i t i s n o t c l e a r f o r m e .

p l e a s e e x p l a i n i t b i t m o r e!

Commented by MJS last updated on 18/Apr/19

a + b i \in R^{2} (= the complex plane)

{there}^{'} s no other possibility to give it a graphical

equivalent than the point (\begin{matrix} a \\ b \end{matrix}) with a, b \in R

\Rightarrow (\begin{matrix} a + b i \\ c + d i \end{matrix}) only makes sense as (\begin{matrix} a \\ b \\ c \\ d \end{matrix}) with

a, b, c, d \in R

Commented by behi83417@gmail.com last updated on 18/Apr/19

t h a n k s i n a d v a n c e s i r M J S!