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Q&z _tant (1) thenShouthat Beat B50024 |
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Answer» y:z=tan^-1(y/x); y/x=yx^-1; dz/dx=1/1+(y/x)^2.d/dx( yx^-1)=1/1+(y/x)^2(-yx-2)=y/x^2+y^2;; d^2z/dx^2=-(y/x^2+y^2)^2= y^2/x^4+y^4+2x^2y^2= y^2/y^2(x^4+y^2+2x^2)= 1/( x^4+y^2+2x^2) |
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