AP EAMCET Engineering 2013 Solved Paper

A plane passing through the point (−1,2,3), then its equation is
a(x+1)+b(y−2)+c(z−3)=0 .......(i)
where <a,b,c> are direction ratios of normal to the plane ABC.
So, the normal makes equal angles with coordinate axes
i.e., (a,b,c)=(

1

√3

,

1

√3

,

1

√3

)
Now, from Eq. (i),

1

√3

(x+1)+

1

√3

(y−2) +

1

√3

(z−3)=0
⇒x+y+z−4=0