Question

Am nevoie de ajutor​

Answer 1

$\it I=\int^1_{-1}\ \dfrac{2x+3}{x^2+3x+5}\ dx=\ \int^1_{-1}\ \dfrac{(x^2+3x+5)'}{x^2+3x+5}\ dx=lg(x^2+3x+5)\ \Big|^1_{-1}=\\ \\ \\ = lg(1+3+5)-lg(1-3+5)=lg9-lg3=lg\dfrac{9}{3}=lg3.$