条件sin^2=cosc+1/4,如何求角C
问题描述:
条件sin^2=cosc+1/4,如何求角C
答
1-cos^2C=cosC+1/4,4cos^2C+4cosC-3=0,cosC=-3/2 舍 或 1/2 ; C=60°
条件sin^2=cosc+1/4,如何求角C
1-cos^2C=cosC+1/4,4cos^2C+4cosC-3=0,cosC=-3/2 舍 或 1/2 ; C=60°