T
thantai2015


Tìm GTLN, GTNN của hàm số:
a) $y = {\sin ^2}x + 2\sin x\cos x + 3{\cos ^2}x$
b) $y = {\cos ^2}\left( {x + \dfrac{\pi }{3}} \right) + \dfrac{{\cos \left( {2x - \dfrac{\pi }{6}} \right)}}{2}$
a) $y = {\sin ^2}x + 2\sin x\cos x + 3{\cos ^2}x$
b) $y = {\cos ^2}\left( {x + \dfrac{\pi }{3}} \right) + \dfrac{{\cos \left( {2x - \dfrac{\pi }{6}} \right)}}{2}$