已知函数∫(x)=3sin(2x-π/3),g(x)=4sin(2x+π/3)则函数∫(x)+g(x)的振幅A的值为 A √13 B 5
问题描述:
已知函数∫(x)=3sin(2x-π/3),g(x)=4sin(2x+π/3)则函数∫(x)+g(x)的振幅A的值为 A √13 B 5
C 7 D 13
答
函数f(x)=3sin(2x-π/3),g(x)=4sin(2x+π/3),则f(x)+g(x)=3sin(2x-π/3)+4sin(2x+π/3)=3sin2xcosπ/3-3cos2xsinπ/3+4sin2xcoπ/3+4cos2xsinπ/3=(3/2+2)sin2x+(2√ 3-(3√ 3)/2)cos2x=(7/2)sin2x+(1/2)...