a)
To solve a) we must find the equation of the two lines, let's say that f(x) is the equation of a line on the right, and g(x) is the equation of the line on the left. The inequation would be
[tex]g(x)\le y\le f(x)[/tex]
To find the equations here we can look that g(x) and f(x) are parallel, then they have the same angular coefficient, the function of f(x) would be
[tex]f(x)=mx+b[/tex]
Looking at the graph we can see that b = 4, then
[tex]f(x)=mx+4[/tex]
And we can use the fact that when x = 2 we have f(x) = 0, then
[tex]0=m\cdot2+4\Rightarrow m=-2[/tex]
The function is
[tex]f(x)=-2x+4[/tex]
And for g(x), we just change +4 to -4, then
[tex]g(x)=-2x-4[/tex]
The inequation for the shaded area is
[tex]\begin{gathered} g(x)\le y\le f(x) \\ \\ -2x-4\le y\le-2x+4 \end{gathered}[/tex]
b)
For b) it's the same thing, find the line's equation, the system of inequations will be
[tex]\begin{cases}y\le f(x) \\ yWhere f(x) is the crescent function and g(x) the decreasing function.
