函数f(x)=Asin(2x+π/3)(A>0,x∈R)的图像过点P(7π/12,-2)1.求f(x)的解析式 2.已知f(a/2-π/6)=-10/13,(-π/2
问题描述:
函数f(x)=Asin(2x+π/3)(A>0,x∈R)的图像过点P(7π/12,-2)
1.求f(x)的解析式 2.已知f(a/2-π/6)=-10/13,(-π/2
答
(1)∵f(x)的图象过点P(7π/12,-2),
∴f(7π/12)=Asin(2×7π/12+π/3)=Asin(3π/2)=-2,
∴A=2,
故f(x)的解析式为f(x)=2sin(2x+π/3).
(2)∵f(a/2-π/6)=2sina=-10/13,∴sina=-5/13,
∵-π/2