If A= 4i-2j+6k and B= i-2j-3k,what is the angle which the sum of vectors make with x-axis?
The plane 2x+3y-4z=5 intersects the x-axis at (a,0,0), the y-axis at (0,b,0), and the Z-axis at (0,0,c). The value of a+b+c is?