Answer:
56.5
Step-by-step explanation:
hello :
sin x + 2 sin x cosx = 0 equivalent to : sinx(1+2cosx) =0
sinx=0 means : general solution is : x= kπ....k in Z
1+2cosx=0 means : cosx= -1/2 general solution is : x= ±π/6+kπ...k in Z
