If n=4 the value of the expression 28-12+ square root of n divided by 2 is. A. 15
B. 17
C. 17/2
D. 21

Last option

Step-by-step explanation:

Note that when the point is not included in the function is marked with an empty circle, and when the point is included in the function is marked with a filled circle.

From the interval f(x) is represented by the slanted line that cuts the y-axis at

The starting point of the line must be filled and the end point must be empty.

Then, from the interval f(x) is defined by the horizontal line . The starting point of this line is marked with a filled circle because it includes the point

Therefore the correct option is option D or the last graph (from left to right)