Question

Hàm số \(y = \frac{{x + 3}}{{x + 2}}\) có đạo hàm là

A. \(y' = \frac{1}{{{{\left( {x + 2} \right)}^2}}}\).     

B. \(y' = \frac{5}{{{{\left( {x + 2} \right)}^2}}}\).  

C. \(y' = \frac{{ - 1}}{{{{\left( {x + 2} \right)}^2}}}\).                       

D. \(y' = \frac{{ - 5}}{{{{\left( {x + 2} \right)}^2}}}\).

 

Answer 1

\(y=\dfrac{x+3}{x+2}\)

=>\(y'=\dfrac{\left(x+3\right)'\left(x+2\right)-\left(x+3\right)\left(x+2\right)'}{\left(x+2\right)^2}=\dfrac{x+2-x-3}{\left(x+2\right)^2}=\dfrac{-1}{\left(x+2\right)^2}\)

=>C