K KEYWEST17 New member Joined Jan 19, 2011 Messages 46 Mar 3, 2011 #1 So far I have (x+y)^-2 Used U substitution U=x+y DU= 0+1 dx y=3 to y=4 (U^-2) DU = U^-1/-1 (x+y)^-1/-1 from y=3 to y=4 From this point on I am stuck. Attachments 20a0227d6de44cd5bca075c5ec856f1.png 1.2 KB · Views: 32
So far I have (x+y)^-2 Used U substitution U=x+y DU= 0+1 dx y=3 to y=4 (U^-2) DU = U^-1/-1 (x+y)^-1/-1 from y=3 to y=4 From this point on I am stuck.
tkhunny Moderator Staff member Joined Apr 12, 2005 Messages 11,325 Mar 3, 2011 #2 \(\displaystyle \int \frac{1}{(x+y)^{2}}\;dx\;=\;-\frac{1}{x+y} + f(y)\) \(\displaystyle \int \frac{1}{(x+y)^{2}}\;dy\;=\;-\frac{1}{x+y} + g(x)\) Why are you substituting anything?
\(\displaystyle \int \frac{1}{(x+y)^{2}}\;dx\;=\;-\frac{1}{x+y} + f(y)\) \(\displaystyle \int \frac{1}{(x+y)^{2}}\;dy\;=\;-\frac{1}{x+y} + g(x)\) Why are you substituting anything?
