Discover Questions

Can someone please prove that (a X (b X c))= (a*c)b-(a*b)c? When weer stem cells first discovered? What is (-3, 3pi/2) as a rectangular cordinates? its already as polar? The radius of a star that has a surface temperature of 27,080 K and is 10000 times brighter than the sun is - Rsun.
Can some explain? How much property was damaged because of the Japanese earthquake in 2011(earthquake alone, no tsunami)?