defence exam Army Havildar SAC Mock Test Series 2025 Mathematics Differential Calculus Evaluation of derivatives
If \( \sqrt{1-x^{2}}+\sqrt{1-y^{2}}=a(x-y) \), then \( \frac{d y}{d x}=\)
1
\( \sqrt{\frac{1-x^{2}}{1-y^{2}}}\)
2
\( \sqrt{\frac{1-y^{2}}{1-x^{2}}}\)
3
\(\sqrt{\frac{1-x^{2}}{1+y^{2}}}\)
4
\( \sqrt{\frac{1+x^{2}}{1-y^{2}}} \)