Jawapan

2015-02-19T23:06:47+08:00
Fg(x)=x^2+4x+5
fg(x)=(x^2+4x+4)+1
fg(x)=(x+2)^2+1
Therefore,g(x)=x+2
If u want check back ur answer u can do this
fg(x)=f(g(x))
      =f(x+2)
      =(x+2)^2+1
      =(x+2)(x+2)+1
      =x^2+4x+4+1
      =x^2+4x+5
1 5 1