$\frac{x^{2}}{a^{2}} + \frac{y^{2}}{b^{2}} = 1$   উপবৃত্তটির পরামিতিক স্থানাঙ্ক-

$\begin{array}{l}x=a \cos \theta \\ \frac{x^{}}{a}=\cos \theta \\ \frac{x^{2}}{a^{2}}=\cos ^{2} \theta….(i)\end{array}$

$\begin{array}{l}y=b \sin \theta \\ \frac{y}{b}=\sin \theta \\ \frac{y^{2}}{b^{2}}=\sin ^{2} \theta…(ii)\end{array}$

$\begin{array}{l}\text { (1) }নং:+ \text { (2) }নং : \Rightarrow \\ \sin ^{2} \theta+\cos ^{2} \theta=\frac{x^{2}}{a^{2}}+\frac{y^{2}}{b} \\ \therefore \frac{x^{2}}{a^{2}}+\frac{y^{2}}{b^{2}}=1 \text {যা উপবৃত্তের সমীকরণ } \\\end{array}$