2007-II-21
Ans: D
$\begin{array}{cl}
& \dfrac{\cos A}{\sin A} +
… Read $\begin{array}{cl}
& \dfrac{\cos A}{\sin A} +
$\begin{array}{rcl}
\angle ABC
II has $4$-fold rotatio
Note that $x=1$ and $y=1$. Hence, we have
$\begin{arr
Not
$\begin{array}{cl}
=
$\begin{array}{rcl}
\