math11

Thanks Melody and CPhill!

That one made me think !

I draw a horizonatal line at y=3

The graph crosses this at thre points,

Approx     x=-3,     x=1    and     x=4.5

So when does 

f(x)=-3    NEVER

f(x)=1     at   x=-1

f(x)=4.5   at   x=2.5

So there are 2 solutions.    x=-1    and      x =  2.5

This can be a little confusing....

f(f(x))   = 3  when f(x)  = -3 and f(x)  = 1   and f(x) = 4.5

When f(x)  = -3   the value of x is off the graph

And when f(x)  = 1, x = -1

And when f(x) = 4.5 , x = 2.5

So x = -1   and x = 2.5