Comparing the functions 7x² and (1/7)x², we can see that in the second one we need bigger values of x to achieve higher values of y, while the first function has higher values of y for smaller values of x.
Therefore, the function 7x² is narrower because the constant of x² is bigger than the constant in the function (1/7)x², so the function values will increase higher, making the graph narrower.
Sketching both functions, we have: