解由y=3tan（π/6－x/4）
=-3tan（x/4-π/6）
故當(dāng)kπ-π/2≤x/4-π/6≤kπ+π/2,k屬于Z時(shí),函數(shù)是減函數(shù)
即當(dāng)kπ-π/3≤x/4≤kπ+2π/3,k屬于Z時(shí),函數(shù)是減函數(shù)
當(dāng)4kπ-4π/3≤x≤4kπ+8π/3,k屬于Z時(shí),函數(shù)是減函數(shù)
故
函數(shù)y=3tan（π/6－x/4）的單調(diào)遞減區(qū)間
[4kπ-4π/3,4kπ+8π/3],k屬于Z.不能取等號(hào)吧哦，忘了兩邊不能去等好的。