Answer:

Step-by-step explanation:
The equation of a parabola in vertex form:

<em>(h, k)</em><em> - vertex</em>
The focus is

We have the vertex (2, -5) and the focus (2, -4).
Calculate the value of <em>a</em> using 
<em>k = -5</em>
<em>add 5 to both sides</em>
<em>multiply both sides by 4</em>


Substitute

to the vertex form of an equation of a parabola:

The standard form:

Convert using


<em>use the distributive property: a(b+c)=ab+ac</em>

Answer:
y = 1/2x - 7
Step-by-step explanation:
y = 1/2x + b
-4 = 1/2(6) + b
-4 = 3 + b
-7 = b
The Answer of <span>−2cos2π91 =</span> is -2
I don't know it's so difficult