Given a cube ABCD.EFGH. if α is the angle BEH & BEG , find the value of cos α ?


Question and Answers Forum

All Questions Topic List
Mensuration Questions
Previous in All Question Next in All Question
Previous in Mensuration Next in Mensuration
Question Number 105356 by bemath last updated on 28/Jul/20

$G i v e n a c u b e A B C D . E F G H .$ $i f α i s t h e a n g l e B E H & B E G,$ $f i n d t h e v a l u e o f \cos α ?$
	Answered by john santu last updated on 28/Jul/20

	Commented byjohn santu last updated on 28/Jul/20

	$w i t h n o r m a l v e c t o r {\vec{n}}_{1} & {\vec{n}}_{2}$ ${\vec{n}}_{1} = \| \begin{matrix} - 2 0 0 \\ 0 2 - 2 \end{matrix} \| = (0, - 4, - 4)$ ${\vec{n}}_{2} = \| \begin{matrix} 0 2 - 2 \\ - 2 2 0 \end{matrix} \| = (4, 4, 4)$ $\cos α = \frac{∣ {\vec{n}}_{1} \circ {\vec{n}}_{2} ∣}{∣ {\vec{n}}_{1} ∣ . ∣ {\vec{n}}_{2} ∣} = \frac{32}{4 \sqrt{2} . 4 \sqrt{3}} = \frac{\sqrt{6}}{3}$ $(J S ♠ ⧫)$
	Commented bybemath last updated on 28/Jul/20

	$g r e a t . .$
Terms of Service
Privacy Policy
Contact: info@tinkutara.com

Question and Answers Forum