Find the equation of the plane passing through ( 1,2,13) and ( 2,-2,1) and parallel to x-axis
Find the included angle between the two planes 2x+y+2z-4=0 and x+y+5=0
Find the included angle between the two planes 2x+y+2z-4=0 and x+y+5=0
prove that if x and y are odd positive integers then x^2+y^2 is even but not divisible by 4