find k if the deteminant of (((3 k)),((2 3)) ) is 2 can someone please teach me how to find the deteminant of a 3×3 matrix ?


Question and Answers Forum

All Questions Topic List
Others Questions
Previous in All Question Next in All Question
Previous in Others Next in Others
Question Number 33425 by Rio Mike last updated on 16/Apr/18

$f i n d k i f t h e d e t e m i n a n t o f$ $(\begin{matrix} 3 k \\ 2 3 \end{matrix}) i s 2$ $c a n s o m e o n e p l e a s e t e a c h m e h o w$ $t o f i n d t h e d e t e m i n a n t o f a 3 \times 3$ $m a t r i x ?$
Commented by Joel578 last updated on 16/Apr/18

$9 - 2 k = 2$ $k = \frac{7}{2}$
Commented by Joel578 last updated on 16/Apr/18

$For 3 \times 3 matrice, you can learn from youtube or$ $textbooks$
Commented by prof Abdo imad last updated on 17/Apr/18

$i f A = (\begin{matrix} a b c \\ e f g \end{matrix})$ $(k l m$ $d e t A = a ∣_{l m}^{f g} ∣ - e ∣_{l m}^{b c} ∣ + k ∣_{f g}^{b c} ∣$ $= a (f m - l g) - e (b m - l c) + k (b g - f c) l e t t a k e$ $e x a m p l e$ $A = (\begin{matrix} 1 - 1 o \\ 2 1 3 \end{matrix})$ $(- 1 2 4)$ $d e t A = 1 ∣_{2 4}^{1 3} ∣ - 2 ∣_{2 4}^{- 1 0} ∣ + (- 1) ∣_{1 3}^{- 1 0} ∣$ $= 4 - 6 - 2 (- 4) - 1 (- 3)$ $= - 2 + 8 + 3 = 9 .$
	Answered by MJS last updated on 16/Apr/18

	$d e t (\begin{matrix} a & b \\ c & d \end{matrix}) = a d - b c$ $d e t (\begin{matrix} a & b & c \\ d & e & f \\ g & h & i \end{matrix}) =_{- (a f h + b d i + c e g)}^{(a e i + b f g + c d h) -}$
Terms of Service
Privacy Policy
Contact: info@tinkutara.com

Question and Answers Forum