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यदि (If) `cosx=(1-t^(2))/(1+t^(2))` तथा (and) `siny=(2t)/(1+t^(2)),0 le t le 1` सिद्ध करें कि (Prove that) `(d^(2)y)/(dx^(2))`, t से स्वतंत्र है | |
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Answer» दिया है, `x=cos^(-1)(1-t^(2))/(1+t^(2))` `:." "x=2 tan^(-1)t" ":." "(dx)/(dt)=(2)/(1+t^(2))" "...(1)` तथा `y=sin^(-1)(2t)/(1+t^(2))=2 tan^(-1)t` `:." "(dx)/(dt)=(2)/(1+t^(2))" "...(2)` अब, `(dy)/(dx)=((dy)/(dt))/((dx)/(dt))=((2)/(1+t^(2)))/((2)/(1+t^(2)))=1` `:." "(d^(2)y)/(dx^(2))=0`, जो कि t से स्वतंत्र है | Second method : यहाँ `x=2 tan^(-1)t` तथा `y=2tan^(-1)t` `:." "y=x" ":." "(dy)/(dx)=1" ""अत: "(d^(2)y)/(dx^(2))=0` |
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