Proof of Solutions for y' = xg(x,y) Equation

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Given the equation y'= xg(x,y) , suppose that g and (partial) dg/dy are defined and continuous for all (x,y). Show the following:

1) y(x)=0 is a solution

2)if y=y(x), x in (a,b) is a solution and if y(x0)>0, x0 in (a,b), then y(x)>0 for all x in (a,b)

Please i need your help.
 
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Fibonacci88 said:
Given the equation y'= xg(x,y) , suppose that g and (partial) dg/dy are defined and continuous for all (x,y). Show the following:

1) y(x)=0 is a solution
You can't- it's not true. For example, supose g(x,y)= 1 so the equation is y'= x. Then y(x)= (1/2)x^2+ C. y(x)= 0 is not a solution since then y'= 0 and so y'= 0\ne x. there may be some other condition that you have left out.

2)if y=y(x), x in (a,b) is a solution and if y(x0)>0, x0 in (a,b), then y(x)>0 for all x in (a,b)

Please i need your help.
 
sorry for mistake. I am sending the correct version of the problem now.

i need answer for (ii) and (iii)
 

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There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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