Question

if X= a sin theta , y= b cos theta , evaluate b²x²+a²y²​

Answer 1

$x = asin \theta \\ y = bcos \theta \\ now \: \: \: {b}^{2} {x}^{2} + {a}^{2} {y}^{2} = {b}^{2} {a}^{2} {sin}^{2} \theta + {a}^{2} {b}^{2} {cos}^{2} \theta \\ = {a}^{2} {b}^{2} ( {sin}^{2} \theta + {cos}^{2} \theta) \\ = {a}^{2} {b}^{2}$

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