Show that the origin lies in the interior of the acute angle between planes x + 2y + 2z = 9 and 4x - 3y + 12z + 13 = 0. Find the equation of bisector of the acute angle.

Explanation

`(x+2y+2z-9)/(sqrt(1^2 + 2^2+ 2^2))= +- (4x-3y+12z+13)/(sqrt(4^2 + 3^2 + 12^2))`

`(x+2y+2z-9)/3 = +- (4x-3y+12x+13)/13`

for`+`unit

`13x+26y+26z-117 = 12x - 9y + 36z+34`

`x+35y-10z-158=0`

for `-` unit

`13x+26y+26z-117= -12x +9y-36z-39`

`25x+17y+62z-78=0`

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