Please find integral 1/1+cos^2x dx ............................
Ashok Eswar , 6 Years ago
Grade 12
1 Answers
Arun
Last Activity: 6 Years ago
∫1/(1+cos²x)dx =∫1/(cos²x(sec²x+1))dx =∫sec²x/(2+tan²x)dx ... as sec²x = 1+tan²x =∫sec²x/(2(1+tan²x/2)dx =1/2∫sec²x/(1+((tanx)/√2)²)dx let u = (tanx)/√2 so du = sec²x/√2 So the integral becomes: 1/2∫1/(1+u²)√2du =arctanu/√2 + c where c is a constant =arctan((tanx)/√2)/√2 + c