Find the locus of P, if for all values of \(\alpha\) the co-ordinates of a moving point P is (9 cos \(\alpha\) 9 sin \(\alpha\))
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Find the locus of P, if for all values of \(\alpha\) the co-ordinates of a moving point P is (9 cos \(\alpha\) 9 sin \(\alpha\))
(9 cos \(\alpha\), 9 sin \(\alpha\))
Let P (h, k) be any point on the required path
From the given information, we have
h = 9 cos \(\alpha\) and k = 9 sin \(\alpha\)
\(\Rightarrow\) \({{h}\over{9}}\) = cos \(\alpha\) and \({{k}\over{9}}\) = sin \(\alpha\)
\({\left({{h}\over{9}} \right)}^{2}+{\left({{k}\over{9}} \right)}^{2}=cos^2\alpha+sin^2\alpha\)
\(\Rightarrow\) \({{h^2}\over{81}}+{{k^2}\over{81}}=1\) \([\because sin^2\ \alpha+cos^2\ \alpha=1]\)
\(\Rightarrow\) h2+ k2 = 81
\(\therefore\) Locus of (h, k) is x2 + y2 = 81
Find the locus of P, if for all values of \(\alpha\) the co-ordinates of a moving point P is (9 cos \(\alpha\) 9 sin \(\alpha\))