解由题可知
2kπ+π/2≤-1/2x+π/4≤2kπ+3π/2
2kπ+π/4≤-1/2x≤2kπ+5π/4
2kπ-π/2≤x≤2kπ+π/2
函数y=1+sin(-1/2x+π/4)的单调减区间为[2kπ-π/2,2kπ+π/2]2kπ-π/2≤x≤2kπ+π/2，除以一个负数应该变号吧是啊。要变号啊，周期变了，上面的错了4kπ-5π/2≤x≤4kπ-π/2