CBSE
2026
Class Class 10 · Mathematics
3 Marks · Short
✅ Verified
(A) If $x = h + a\cos\theta$, $y = k + b\sin\theta$, then prove that: $\left(\frac{x-h}{a}\right)^2 + \left(\frac{y-k}{b}\right)^2 = 1$
✅ Answer & Solution
Given: $x = h+a\cos\theta \Rightarrow \cos\theta = \frac{x-h}{a}$. Also: $y = k+b\sin\theta \Rightarrow \sin\theta = \frac{y-k}{b}$. Squaring and adding both: $\cos^2\theta+\sin^2\theta = \left(\frac{x-h}{a}\right)^2+\left(\frac{y-k}{b}\right)^2$. Since $\sin^2\theta+\cos^2\theta=1$ (identity): $\left(\frac{x-h}{a}\right)^2+\left(\frac{y-k}{b}\right)^2 = 1$ (Proved)
✅ Verified by Super Admin