vikas askiitian expert
Last Activity: 14 Years ago
f(x)= 3+4cosx/(4+3cosx)^2
putting cosx=1-tan^2(x/2) /1+tan^2(x/2)
[from cos2x=1-tan^2(x)/1+tan^2(x)]
f(x) becomes 7-tan^2(x/2) .sex^2(x/2)/7+tan^2(x/2)
I= int [7-tan^2(x/2) . sex^2(x/2)/7+tan^2(x/2)]
put tanx/2 =t
after differentiating we get
sex^2(x/2)dx=dt
putting in previous eq we get
I= int 7-t^2/7+t^2 or -(t^2-7)/(t^2+7)
= int t^2+7-14/t^2+7
=int { (1) -(14/t^2+7) } after separating int 1/x^2+a^2 =1/ataninverse(x/a)
= t - 14/root7taninverse(t/root7) + c
again substituting value of t we get
I =tanx/2 - 2root7(taninverse{tan(x/2))/root7} +c