Biểu thức $\displaystyle A=\frac{2{{\cos }^{2}}2\alpha +\sqrt{3}\sin 4\alpha -1}{2{{\sin }^{2}}2\alpha +\sqrt{3}\sin 4\alpha -1}$ có kết quả rút gọn là
A. $\displaystyle \frac{\cos \left( 4\alpha +30{}^\circ \right)}{\cos \left( 4\alpha -30{}^\circ \right)}.$
B. $\displaystyle \frac{\cos \left( 4\alpha -30{}^\circ \right)}{\cos \left( 4\alpha +30{}^\circ \right)}.$
C. $\displaystyle \frac{\sin \left( 4\alpha +30{}^\circ \right)}{\sin \left( 4\alpha -30{}^\circ \right)}.$
D. $\displaystyle \frac{\sin \left( 4\alpha -30{}^\circ \right)}{\sin \left( 4\alpha +30{}^\circ \right)}.$
A. $\displaystyle \frac{\cos \left( 4\alpha +30{}^\circ \right)}{\cos \left( 4\alpha -30{}^\circ \right)}.$
B. $\displaystyle \frac{\cos \left( 4\alpha -30{}^\circ \right)}{\cos \left( 4\alpha +30{}^\circ \right)}.$
C. $\displaystyle \frac{\sin \left( 4\alpha +30{}^\circ \right)}{\sin \left( 4\alpha -30{}^\circ \right)}.$
D. $\displaystyle \frac{\sin \left( 4\alpha -30{}^\circ \right)}{\sin \left( 4\alpha +30{}^\circ \right)}.$
Loga
Hóa Học lớp 12
