Recent content by Philip Lam

Let a and b be the vectot , let v be the angle between a and b, then aXb=a*b*sin(v) a.b=a*b*cos(v) (axb)*(axb)= a^2*b^2*sin(v)^2=a^2*b^2*(1-cos(v)^2)=a^2*b^2-(a.b)^2 let c=a-b, then the area of triangle a,b,c is F=(1/2)*a*b*sin(v) F^2 = (1/4)*a^2*b^2*sin(v)^2 =...