Answer:

Step-by-step explanation:
we have

This is the equation of a vertical parabola open upward
The vertex is a minimum
The equation of a vertical parabola in vertex form is equal to

where
(h,k) is the vertex
Convert the given function to vertex form
Factor the leading coefficient

Complete the square


Rewrite as perfect squares
------> equation in vertex form
The vertex is the point (2,6)
Answer:
m∠B = 31°
Step-by-step explanation:
First, find the measure of angle ACB by subtracting its supplement from 180 degrees:
180 - 113 = 77
m∠ACB = 77°
Then subtract both m∠A and m∠ACB from 180 degrees, since the interior angles of a triangle always add to 180°:
m∠B = 180° - 72° - 77°
m∠B = 31°
The numbers are irrational, so I can't write them exactly with digits.
When rounded to the nearest ten-thousandth, they are
31.3746
and
-6.3746 .