首页 > 留学知识库

问题: f(x)=pai/2-2arcsin(2x 1),f-1(-pai/2)=?

解答:

f-1(-π/2)=?
解:
由:y=f(x)=π/2-2arcsin(2x+1)
有:arcsin(2x+1)=(π/4)-y/2
sin[arcsin(2x+1)]=sin[(π/4)-y/2]
2x+1=sin[(π/4)-y/2]
x=(1/2){sin[(π/4)-y/2]-1}
既:f-1(x)=(1/2){sin[(π/4)-y/2]-1}
所以:
f-1(-π/2)
=(1/2){sin[(π/4)+(π/4)]-1}
=(1/2)(-1)
=-1/2