prove that b x a = -a x b
i know how to do it if i make like an example with numbers but how can i show this otherwise? anyone want to start off the proof for me, i'm just kind of stuck
thank you very much
sorry for bugging you i just have one more question i promise
i am finding the area of the triangle with vertices (0,6,0) (-5,7,1) and (2,1,2)
i got a= (5,-1,-1) and b= (7,-6,1)
and i think the formula is A= 1/2 ll a x b ll
so then i did the square root of the determinates squared and got the square root of (-5)^2 + (-2)^2 + (37)^2 which is definitely not right
the answer is 19/sqrt of 2...