1 - x⁴ = (1 + x²)(1 - x²)
integral[ ( √(1 + x²) + √(1 - x²) )dx / √( (1 + x²)(1 - x²) ) ]=
integral[ √(1 + x²)dx / √( (1 + x²)(1 - x²) )] + integral[ √(1 - x²)dx / √( (1 + x²)(1 - x²) )] =
A + B
A =
integral[ √(1 + x²)dx / √( (1 + x²)(1 - x²) )] =
integral[ ( √( (1 + x²) /( (1 + x²)(1 - x²) ) ) * dx] =
integral[ ( √( 1 /(1 - x²) ) * dx] =
integral[ ( ( 1 /√(1 - x²) ) * dx] =
arcsin(x) + c
B =
integral[ √(1 - x²)dx / √( (1 + x²)(1 - x²) )] =
integral[ ( √( (1 - x²) /( (1 + x²)(1 - x²) ) ) * dx] =
integral[ ( √( 1 /(1 + x²) ) * dx] =
integral[ ( ( 1 /√(1 + x²) ) * dx] =
ln|x + √(x²±1)| + ĉ
A + B = arcsin(x) + c + ln|x + √(x²±1)| + ĉ = arcsin(x) + ln|x + √(x²±1)| + C, где C = с + ĉ, c,ĉєŔ