Question

9x+y=10 convert to a polar equation in terms of r and theta

Answer 1

$\bf 9x+y=10\qquad \begin{cases} x=rcos(\theta)\\ y=rsin(\theta) \end{cases}\implies 9rcos(\theta)+rsin(\theta)=10 \\\\\\ r[9cos(\theta)+sin(\theta)]=10\implies r=\cfrac{10}{9cos(\theta)+sin(\theta)}$

recall, polars are written as "r" in θ terms