ExamBro
ExamBro
MHT CET · Maths · Straight Lines

The equation of a line passing through \((\rho \cos \propto, p \sin \propto)\) and making an angle \((90+\propto)\) with positive direction of \(\mathrm{X}\)-axis is

  1. A \(x \cos \propto-y \sin \propto=2 p\)
  2. B \(x \sin \propto+y \cos \propto=p\)
  3. C \(x \cos \propto+y \sin \propto=p\)
  4. D \(\mathrm{x} \cos \propto+\mathrm{y} \sin \propto=3 \mathrm{p}\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(x \cos \propto+y \sin \propto=p\)

Step-by-step Solution

Detailed explanation

Slope of line \(=\tan (90+\propto)=-\cot \propto\)
Equation of required line is
\(
\begin{aligned}
& (y-p \sin \propto)=\frac{-\cos \propto}{\sin \propto}(x-p \cos \propto) \\
& \therefore(\sin \propto) y-p \sin ^2 \propto=(-\cos \propto) x+p \cos ^2 \propto \\
& \therefore(\operatorname{Cos} \propto) x+(\sin \propto) y=p
\end{aligned}
\)