Question

This is one requires substitution, but i don't what i am doing wrong...

Answer 1

\[yy \prime+x=(x ^{2}+y ^{2})^{1/2}\]

Answer 2

i tried subsitituting \[u = x ^{2}+y ^{2}\]

Answer 3

@UnkleRhaukus

Answer 4

why did you think of that substitution?

Answer 5

because it would simplify the right side tremendously...but not too sure.

Answer 6

but what would y' become?

Answer 7

\[(1/y)((du/dx)-x)\]

Answer 8

but when i substitute it get very messy.

Answer 9

substitute and try that simplification again

Answer 10

the mess should work it self out

Answer 11

ok thanks!

Answer 12

tell me what you get,

Answer 13

this is what i have so far...

Answer 14

\[1/y \left( (u-x ^{2})^{1/2} - x(u-x ^{2})^{1/2} \right) + x = u ^{1/2}\]

Answer 15

oh wait ....i forgot about that y

Answer 16

got it!

Answer 17

i get c.

Answer 18

thank you very much!

Answer 19

\[u'=√u\]