cot 45°+ cot(π+45°)+cot (2π+45°)+..........+cot(9π+45°) এর মান কোনটি?

$\begin{array}{l}\text { }^{} \cot 45^{0}+\cot \left(\pi+45^{\circ}\right)+\cot (2 \pi \\ \left.+45^{0}\right)+\cdots \cdots+\cot \left(9 \pi+45^{\circ}\right) \\ =(9+1) \cot 45^{\circ}=10 \therefore 1=10 \text { }\end{array}$