Find the angle between the planes `2x+y-2x+3=0 and vecr*(6hati+3hatj+2hatk)=5`.

Explanation

Normals along the given planes are `2hati+hatj-2hatk and 6hati+3hatj+2hatk`.
Then angle between planes, `theta = cos^(-1)=((2hati+hatj-2hatk)*(6hati+3hatj+2hatk))/(sqrt((2)^(2)+(1)^(2)+(-2)^(2))sqrt((6)^(2)+(3)^(2)+(2)^(2)))=cos^(-1)""(11)/(12)`