Formula : The equation of mid parallel plane is , say
Plane 1:ax + by + cz + d1 = 0 &
Plane 2:ax + by + cz + d2 = 0 is given by the formula
Mid parallel plane = ax + by + cy + \(\frac{(d_1+d_2)}2\) = 0
where (d1,d2) are constants of the planes
Therefore ,
First Plane 2x – 3y + 6z + 21 = 0 …… (1)
Second plane 2x – 3y + 6z – 14 = 0 …… (2)
Using equation (1) and (2)
Mid parallel plane = 2x - 3y + 6x + \(\frac{21-14}2\) = 0
4x – 6y + 12z + 7 = 0