which statement is true for all functions f(x)
1. the graph of f(x) + k is the graph of f(x) shifted left or right by | k | units
2. the graph of -f(x) is the graph of f(x) reflected over the x-axis
3. the graph of -f(x) is the graph of f(x) reflected over the y-axis
4. the graph of f(kx) is the graph of f(x) shifted left or right by | k | units
