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If lim x tends to y , solve xsiny-ysinx ÷ x-y |
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Answer» If I write the problem, it will be like this:Lim (y->0) {Lim (x->0) (x sin y - y sin x) / (x2 + y2)}.And calculate the FIRST limit we getLim (y->0) 0 = 0.Since x and y both approach 0, we can take the sin(u)=u-u^3/6 approximation as close enough for small u. Then(x*sin(y)-y*sin(x))/(x^2+y^2)=(x*(y-y^3/6)-y*(x-x^3/6))/(x^2+y^2)=(x*y^3-x^3*y)/(6*(x^2+y^2))=x*y*(y^2-x^2)/(6*(x^2+y^2)) Now we can see how this behaves by noting the 3 cases y>>x, y< |
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