How do you integrate int (t^2 + 8) / (t^2 - 5t + 6) using partial fractions?

1 Answer
May 27, 2016

=t-12ln|(t-2)|+17ln|(t-3)|+c ,where c = integration constant

Explanation:

I=int (t^2 + 8) / (t^2 - 5t + 6)dt

=int ((t^2 -5t+ 6)+(5t+2)) / (t^2 - 5t + 6)dt

=int (t^2 -5t+ 6)/ (t^2 - 5t + 6)dt+int(5t+2) / "(t-3)(t-2)"dt

Now
Let axx(t-3)+bxx(t-2)=5t+2

for t= 3 ,
axx(3-3)+bxx(3-2)=5xx3+2=>b=17

for t= 2 ,
axx(2-3)+bxx(2-2)=5xx2+2=>a=-12

I=intdt+int(-12xx(t-3)+17xx(t-2)) / "(t-3)(t-2)"dt

=intdt-12int(dt)/(t-2)+17int(dt)/(t-3)

=t-12ln|(t-2)|+17ln|(t-3)|+c ,where c = integration constant