~~For vectors a⃗ and b⃗ , both of the same dimensions and based at the same point, show that they satisfy
||a+b|| 2 +2||a+b|| = 2||a||2+2||b|| 2
~~Note: you must prove this identity without using components; use only vector notation and vector operations!
Calculate
dist(Q,Π)
where, Q(2,1,1), and Π is determined by the normal vector to the plane n⃗ =(2,6,9)P and the point P(8,−3,1) lies on the plane.