Tính đạo hàm của hàm số lượng giác sau $y = \sqrt {{{\sin }^3}\left( {2x – \frac{\pi }{3}} \right) + 1} $
A. $y’ = \frac{{3{{\sin }^2}\left( {2x – \frac{\pi }{3}} \right)\cos \left( {2x – \frac{\pi }{3}} \right)}}{{2\sqrt {{{\sin }^3}\left( {2x – \frac{\pi }{3}} \right) + 1} }}$
B. $y’ = \frac{{{{\sin }^2}\left( {2x – \frac{\pi }{3}} \right)\cos \left( {2x – \frac{\pi }{3}} \right)}}{{2\sqrt {{{\sin }^3}\left( {2x – \frac{\pi }{3}} \right) + 1} }}$
C. $y’ = \frac{{{{\sin }^2}\left( {2x – \frac{\pi }{3}} \right)\cos \left( {2x – \frac{\pi }{3}} \right)}}{{\sqrt {{{\sin }^3}\left( {2x – \frac{\pi }{3}} \right) + 1} }}$
D. $y’ = \frac{{3{{\sin }^2}\left( {2x – \frac{\pi }{3}} \right)\cos \left( {2x – \frac{\pi }{3}} \right)}}{{\sqrt {{{\sin }^3}\left( {2x – \frac{\pi }{3}} \right) + 1} }}$
Hướng dẫn giải
Chọn D.
Ta có: $y’ = \frac{{3{{\sin }^2}\left( {2x – \frac{\pi }{3}} \right)\cos \left( {2x – \frac{\pi }{3}} \right)}}{{\sqrt {{{\sin }^3}\left( {2x – \frac{\pi }{3}} \right) + 1} }}$ .