若关于k的方程16(k+2)=x﹣13(k+1)的解是k=﹣4,则x的值为 ____
They visited the park last month.
____ ____they____the park?
函数fx=2sin2x+π4定义在0,π2上,则f(x)的值域____ ;f(x)的减区间是____ .