G girlkute New member Xu 0 5/7/13 #1 a/ 5cos(2x+pi/3) = 4sin(5pi/6 - x) - 9 b/cos bình 2x - 2cos(x+3pi/4).sin(3x-pi/4) = 2
Spider_man New member Xu 0 5/7/13 #2 5cos(2x+pi/3) = 4sin(5pi/6 - x) - 9 Nhấn để mở rộng... Đặt \[t=x+\frac{\pi }{6}\] \[\Leftrightarrow 5cos(2x+\frac{\pi }{3})=4sin(x+\frac{\pi }{6})-9\Leftrightarrow 5cos2t=4sint-9 \]
5cos(2x+pi/3) = 4sin(5pi/6 - x) - 9 Nhấn để mở rộng... Đặt \[t=x+\frac{\pi }{6}\] \[\Leftrightarrow 5cos(2x+\frac{\pi }{3})=4sin(x+\frac{\pi }{6})-9\Leftrightarrow 5cos2t=4sint-9 \]