The polar equation of the line perpendicular to the line $\sin \theta-\cos \theta=\frac{1}{r}$ and passing…
- $\sin \theta+\cos \theta=\frac{\sqrt{3}+1}{r}$
- $\sin \theta-\cos \theta=\frac{\sqrt{3}+1}{r}$
- $\sin \theta+\cos \theta=\frac{\sqrt{3}-1}{r}$
- $\cos \theta-\sin \theta=\frac{\sqrt{3}}{r}$
Solution

and point $(2, \pi / 6)$ Let $\quad x=r \cos \theta=2 \cdot \cos \pi / 6=\sqrt{3}$ and $y=r \sin \theta=2 \cdot \sin \pi / 6=1$ The cartesian point is $(\sqrt{3}, 1)$. Now, we change the polar of line into cartesian form i.e., $r \sin \theta-r \cos \theta=1$

Equation of perpendicular line to Eq. (ii) is

which passes through $(\sqrt{3}, 1)$ $\lambda=\sqrt{3}+1$ From Eq. (iii), we get $x+y=\sqrt{3}+1$ Now, we convert this into polar form $\begin{aligned} r \cos \theta+r \sin \theta & =\sqrt{3}+1 \\ \Rightarrow \quad \sin \theta+\cos \theta & =\frac{\sqrt{3}+1}{r}\end{aligned}$
Asked in: AP EAMCET 2011