Question: how many of the following curves are characteristic curves of the equation (i) (
how many of the following curves are characteristic curves of the equation
yu_{x}-xu_{y}+u=-1
(i) x^{2}-y^{2}=11
(ii) x^{}2 + y^{}2 = 3
(iii) x^{}2 + y^{}2 = 6
(iv) x+y^{}2 =2
v)yx^{2}=6
vi)x^{2}+y^{2}=17