ANSWER
To graph the function
[tex]f(x)=\left \{ {{x+4\:\:if\:\:-4\leq x<3} \atop {2x-1\:\:if\:\:3\leq x<6}} \right.[/tex]
follow the steps below.
1. Find y- intercept by plugging in [tex]x=0[/tex].
[tex]x=0[/tex] is on the interval, [tex]-4\leq x<3[/tex], so we substitute in to
[tex]f(x)=x+4[/tex]
[tex]\Rightarrow f(0)=0+4[/tex]
[tex]\Rightarrow f(0)=4[/tex]
Hence the y-intercept is [tex](0,4)[/tex]
2. Find x-intercept by setting [tex]f(x)=0[/tex]
This implies that
[tex]x+4=0,[/tex] on [tex]-4\leq x<3[/tex]
or
[tex]2x-1=0[/tex] on [tex]3\leq x <6[/tex]
We now solve for [tex]x[/tex] on each interval,
[tex]x=-4,[/tex] on [tex]-4\leq x<3[/tex]
or
[tex]x=\frac{1}{2}[/tex] on [tex]3\leq x <6[/tex]
But observe that
[tex]x=\frac{1}{2}[/tex] does not belong to [tex]3\leq x <6[/tex]
This means it can never be an intercept for this piece-wise function.
Hence our x-intercept is [tex](-4,0)[/tex]
3. Plotting the boundaries of the interval.
For [tex]f(x)=x+4[/tex] on [tex]-4\leq x<3[/tex]
[tex]f(-4)=-4+4[/tex]
[tex]\Rightarrow f(-4)=0[/tex].
This point [tex](-4,0)[/tex] coincides with the x-intercept.
[tex]f(3)=3+4[/tex]
[tex]f(3)=7[/tex]
So we have the point [tex](3,7)[/tex]. But note that [tex]x=3[/tex] does not belong to this interval so we plot this point as a hole.
For [tex]f(x)=2x-1[/tex] on [tex]3\leq x <6[/tex]
[tex]f(3)=2(3)-1[/tex]
[tex]\Rightarrow f(3)=5[/tex]
So we plot [tex](3,5)[/tex]
[tex]f(6)=2(6)-1[/tex]
[tex]\Rightarrow f(6)=11[/tex]
So we plot [tex](6,11)[/tex] also as a hole.
Plotting all these points we can now graph the function,
[tex]f(x)=\left \{ {{x+4\:\:if\:\:-4\leq x<3} \atop {2x-1\:\:if\:\:3\leq x<6}} \right.[/tex]
See attachment for graph.