Flag Integral Calculus> definite integral...
question mark

definite integarl of (1+2cosx)/(2+cosx)2dx from 0 to π/2 is?

pihu , 16 Years ago
Grade
anser 1 Answers
Jitender Singh
Ans:
I = \int_{0}^{\pi /2}\frac{(1+2cosx)}{(2+cosx)^{2}}dx
t = tan\frac{x}{2}
dt = \frac{1}{2}sec^{2}\frac{x}{2}dx
sinx = \frac{2t}{1+t^{2}}, cosx = \frac{1-t^{2}}{1+t^{2}}
I = \int_{0}^{1} \frac{-2(t^{2}-3)}{t^{4}+6t^{2}+9}dt
I = -2\int_{0}^{1} ((\frac{1}{t^{2}+3})-(\frac{6}{(t^{2}+3)^{2}}))dt
I = (\frac{2t}{t^{2}+3})_{0}^{1} = \frac{1}{2}
Thanks & Regards
Jitender Singh
IIT Delhi
askIITians Faculty
Last Activity: 11 Years ago
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments