Recall the fundamental rule of trig:

So, there exists an angle
such that

if and only if

Working out the numbers, we get

So, there doesn't exist a number
such that

Lets take this step by step.
1-4-x-(4-1)=-x-2-(4)
first, we'll simplify the parentheses on the left side of the equation.
1-4-x-3=-x-2-(4)
second, we'll combine like terms on the left side.
-6-x=-x-2-(4)
third, we'll combine like terms on the right side of the equation.
-6-x=-6-x
since these are equal, (x=x), we have infinitely many solutions.
This is so hard im so sry i dont get it