Thi online: 50 bài toán cực trị - Mức độ 3: Vận dụ...

A

\(\dfrac{{5 - \sqrt 5 }}{2}\).                                         

B

\(\dfrac{{1 + \sqrt 5 }}{2}\).                                   

C

\(2 + \sqrt 5 \).                    

D   \( - 1 + \sqrt 5 \).

A

  \(m \in \left( {\dfrac{{2 - 2\sqrt 7 }}{3}; - 1} \right) \cup \left( {2;\dfrac{{2 + 2\sqrt 7 }}{3}} \right)\)                      

B

 \(m \in \left( {\dfrac{{2 - 2\sqrt 7 }}{3};\dfrac{{2 + 2\sqrt 7 }}{3}} \right)\)

C

 \(m \in \left( { - 1;2} \right)\)

D  \(m \in \left( { - \infty ; - 1} \right) \cup \left( {2; + \infty } \right)\)    

A 4

B \(\dfrac{2}{3}\).

C \(1\).

D \(5\).

A \(\dfrac{7}{2}\).

B \( - 1\).

C \(\dfrac{1}{2}\).

D 5.