-->

Three Dimensional Geometry

Question
CBSEENMA12033388

Find the vector equation of the plane which is at a distance of fraction numerator 6 over denominator square root of 29 end fraction from the origin and its normal vector from the origin is 2 space straight i with hat on top space minus space 3 space straight j with hat on top space plus space space 4 space straight k with hat on top. Also find its cartesian form. 

Solution

Here    straight p space equals space fraction numerator 6 over denominator square root of 29 end fraction
and    straight n with rightwards arrow on top space equals space 2 space straight i with hat on top space minus space 3 space straight j with hat on top space plus space 4 space straight k with hat on top
therefore space space space space open vertical bar straight n with rightwards arrow on top close vertical bar space equals space square root of left parenthesis 2 right parenthesis squared plus left parenthesis negative 3 right parenthesis squared plus left parenthesis 4 right parenthesis squared end root space equals space square root of 4 plus 9 plus 16 end root space equals space square root of 29
therefore space space space space space space straight n with hat on top space equals space fraction numerator straight n with rightwards arrow on top over denominator open vertical bar straight n with rightwards arrow on top close vertical bar end fraction space equals space fraction numerator 1 over denominator square root of 29 end fraction left parenthesis 2 straight i with hat on top space minus space 3 space straight j with hat on top space plus space 4 space straight k with hat on top right parenthesis
The required equation of plane is
                 straight r with rightwards arrow on top. space straight n with hat on top space equals space straight p
or               straight r with rightwards arrow on top. space fraction numerator 1 over denominator square root of 29 end fraction space left parenthesis 2 space straight i with hat on top space minus space 3 space straight j with hat on top space plus space 4 space straight k with hat on top right parenthesis space equals space fraction numerator 6 over denominator square root of 29 end fraction
or              stack straight r. with rightwards arrow on top left parenthesis 2 space straight i with hat on top space minus space space 3 space straight j with hat on top space plus space 4 space straight k with hat on top right parenthesis space equals space 6
Taking straight r with rightwards arrow on top space equals space straight x space straight i with hat on top space plus space straight y space straight j with hat on top space plus space straight z space straight k with hat on top comma space we space get
               left parenthesis straight x space straight i with hat on top space plus space straight y space straight j with hat on top space plus space straight z space straight k with hat on top right parenthesis. space space space open parentheses 2 space straight i with hat on top space minus space 3 space straight j with hat on top space plus space 4 space straight k with hat on top close parentheses space equals space 6
or 2x – 3 y + 4 z = 6, which is cartesian equation of plane.