If `x costheta=y sin theta=sqrt(x^(2)+y^(2))` and `(cos^(2)theta)/(a^(2))+(sin^(2)theta)/(b^(2))=(1)/(x^(2)+y^(2))` then the value correct releation is (यदि `x costheta=y sin theta=sqrt(x^(2)+y^(2))` और `(cos^(2)theta)/(a^(2))+(sin^(2)theta)/(b^(2))=(1)/(x^(2)+y^(2))` है तो सही सम्बंद क्या होगा )A. `(x^(2))/(b^(2))-(y^(2))/(a^(2))=1`B. `(x^(2))/(a^(2))-(y^(2))/(b^(2))=1`C. `(x^(2))/(b^(2))-(y^(2))/(a^(2))=1`D. `(x^(2))/(a^(2))-(y^(2))/(b^(2))=1`

If `x costheta=y sin theta=sqrt(x^(2)+y^(2))` and `(cos^(2)theta)/(a^(

1.	If `x costheta=y sin theta=sqrt(x^(2)+y^(2))` and `(cos^(2)theta)/(a^(2))+(sin^(2)theta)/(b^(2))=(1)/(x^(2)+y^(2))` then the value correct releation is (यदि `x costheta=y sin theta=sqrt(x^(2)+y^(2))` और `(cos^(2)theta)/(a^(2))+(sin^(2)theta)/(b^(2))=(1)/(x^(2)+y^(2))` है तो सही सम्बंद क्या होगा )A. `(x^(2))/(b^(2))-(y^(2))/(a^(2))=1`B. `(x^(2))/(a^(2))-(y^(2))/(b^(2))=1`C. `(x^(2))/(b^(2))-(y^(2))/(a^(2))=1`D. `(x^(2))/(a^(2))-(y^(2))/(b^(2))=1`
Answer» Correct Answer - b `cos^(2)theta-sin^(2)theta=(1)/(3)` (given) `cos^(2)theta+sin^(2)theta=1` (property) `(cos^(2)theta-sin^(2)theta)(cos^(2)theta+sin^(2)theta)` `=(1)/(3)xx1` `cos ^(4)theta-sin^(4)theta=(1)/(3)` `therefore ((a^(2)-b^(2))(a^(2)+b^(2))=a^(4)-b^(4))`