4. What is the order, from narrowest to widest graph, of the quadratic functions f(x) = –10x², f(x) = 2x², f(x) = 0.5x²

Question

4.   What is the order, from narrowest to widest graph, of the quadratic functions f(x) = –10x², f(x) = 2x², f(x) = 0.5x²

accessdenied · Answer

Do you have any ideas on this problem so far?

accessdenied · Answer

O...kay.
Imagine starting from x=0 and gradually increasing the x-values.  Which one is getting big most quickly?
Like x=0,  they're all 0.  Then for x=1, suddenly one is -10(1)^2,   one is 2(1)^2,  and the last is 0.5(1)^2.  We can ignore signs (that does not affect the narrowness).

The one getting big most quickly is the narrowest one because it takes a smaller x-value away from x=0 to get a higher function value.
|dw:1395457119302:dw|