函數(shù)f(x)=sin(wx+fai)在它的某一個(gè)周期內(nèi)單調(diào)減區(qū)間[5π/12,11π5/12] |fai|T=π==>w=2π/π=2
∴f(x)=sin(2x+φ)
f(5π/12)=sin(2*5π/12+φ)=1==>5π/6+φ=π/2==>φ=-π/3
∴f(x)=sin(2x-π/3)

(2)解析：將y=f(x)的圖像先向右平移π/6個(gè)單位
g(x)=sin(2(x-π/6)-π/3)=sin(2x-2π/3)
再將圖像上的所有點(diǎn)的橫坐標(biāo)變?yōu)樵瓉?lái)的1/2倍,縱坐標(biāo)不變
T=π==>T=π/2==>w=4
∴g(x)=sin(4x-2π/3)
2kπ-π/2