Mathematics - 3D Coordinate Geometry Question with Solution | TestHub

D.r's of normal to the plane $⟨4-0,-2-0,-5-0⟩\equiv ⟨4,-2,-5⟩$ Hence equation of the plane $4x-2y-5z=\lambda$ But it passes through $(4,-2,-5)$ $\begin{array}{rl}& \Rightarrow 4\times 4-2\times (-2)-5\times (-5)=\lambda \\ & \Rightarrow \lambda =45\end{array}$