evaluate dx/8+2x^2

Answer 1

∫dx/(8+2x^2)
=(1/4)∫(1/2)dx/(1+(x/2)^2)
use y=(x/2), dy=dx/2
=(1/4)∫dy/(1+y²)
=(1/4)atan(y)+C
=(1/4)atan(x/2)+C