Answer:
- y =
+ 7
Step-by-step explanation:
The graph that will lie above the x-axis will be having only positive values throughout its domain,
So, We have to check which graph is having y > 0 for every x.
- y = -
+ 7
clearly y will be negative for many values of x , as coefficient of variable is negative.
- y =
Put x = 0, you will get y as negative .
- y =
Since, Square of anything will always be positive , and here constant term is also positive , so, It will always be positive .
Thus, it is having its graph always above x axis.
- y = x - 7
Put x = 0 , y = -7, which is negative