Team Project Useful Formulas for Two and more Vectors, prove (12) " (16), which are often useful in practical work, and illustrate each formula with tow examples. Show that each side of (13) then equals [" b2c2d1, b1c2d1, 0] and give reasons why the two sides are then equal in any Cartesian coordinate system. For (14) and (15) use (13). Formula (15) is called Lagrangesidentity. a x b = V(aa)(b.b) - (a+b) bx (ex d) = (b.d)c - (b.c)d (12) (13) (14) (a x b) x (ex d) (a b d)c - (a b c)d (a.d)(b.c) (15) (a x b) (cx d) = (a c)(b-d) (16) (a bc)(b ca) = (cab) = -(c b a) = (a e b)