1) f(x) = x + 3
F(x) = x²/2 + 3x + C
2) f(x) = x²+4x -1
F(x) = x³/3 + 4x²/2 - x + C = x³ + 2x² - x + C
3) f(x) = (x³ + x)/(x² + 1) = x(x² + 1)/(x² +1) = x
x² + 1 ≠ 0
f(x) = x
F(x) = x²/2 + C
4) f(x) = 6x² -2x⁻²
F(x) = 6x³/3 -2x⁻¹+ C = 2x³ -2/x + C
5) f(x) = 9/x¹⁰ + 2/x⁹ = 9x⁻¹⁰ + 2x⁻⁹
F(x) = 9x⁻⁹/-9 + 2x⁻⁸/-8 + C = -1/x⁹ -1/(4x⁸) + C