Answer:

Step-by-step explanation:
Apply formula for the circumference of a circle.

The diameter
is 13.8 cm.



Answer:
B. 
Step-by-step explanation:


Answer:
(0, - 1) maximum
Step-by-step explanation:
The vertex is the turning point of the graph.
That is vertex = (0, - 1 )
Since the graph opens down then it is a maximum
Answer:
y=1/2x+5
Step-by-step explanation:
Plug it into the formula for a point and a slope.
(y-(y(subscript 1)))=(m)(x-(x(subscript 1)))
Y-8=1/2(x-6)
Then multiply the 1/2 to the x and -6. After you do that, move everything so that it has y by itself on the left. Your ending should be y=1/2x+5.