A = {2,1,2,4}
B = {4,1,6,2}
angle = arccos( (A.B)/(norm(A)*norm(B)) )
area = (1/2)A.B sin(angle)
Is this correct? if yes, it is easy to generalize for Rn.
Find the area of the triangle with sides
A = (a1 ... an)
B = (b1 ... bn)
and A-B = (a1-b1 ... an-bn)
I don't even know where to start. I know how to do it in 3D with the cross product, but that obviously won't work for higher dimensions.
So I need help generalizing for Rn.
1. Homework Statement
Why does the following ODE ALWAYS have two linearly independent solutions?
x''(t) + a(t) x'(t) + b(t) x(t) = f(t)
The characteristic polynomial argument is not sufficient?
Hello fellow PF members
I was wondering how one would go about finding the lagrangian of a problem like the following:
A particle is constrained to move along the a path defined by y = sin(x).
Would you simply do this:
x = x
y = sin(x)
x'^2 = x'^2
y'^2 = x'^2 (cos(x))^2...