We have been given graph of a downward opening parabola with vertex at point 
. We are asked to write equation of the parabola in standard form.
We know that equation of parabola in standard form is 
.
We will write our equation in vertex form and then convert it into standard form.
Vertex for of parabola is 
, where point (h,k) represents vertex of parabola and a represents leading coefficient.
Since our parabola is downward opening so leading coefficient will be negative.
Upon substituting coordinates of vertex and point (0,0) in vertex form, we will get:
Divide both sides by 
So our equation in vertex form would be 
.
Let us convert it in standard from.
Therefore, the equation of function is standard form would be .
Answer:
6.11km/hr
Step-by-step explanation:
Let the speed that Kelli swims be represented by Y
Speed of the river = 5km/hr
Distance = Speed × Time
Kelli swam upstream for some distance in one hour
Swimming upstream takes a negative sign, hence:
1 hour ×( Y - 5) = Distance
Distance = Y - 5
She then swam downstream the same river for the same distance in only 6 minutes
Downstream takes a positive sign
Converting 6 minutes to hour =
60 minutes = 1 hour
6 minutes =
Cross Multiply
6/60 = 1/10 hour
Hence, Distance =
1/10 × (Y + 5)
= Y/10 + 1/2
Equating both equations we have:
Y - 5 = Y/10 + 1/2
Collect like terms
Y - Y/10 = 5 + 1/2
9Y/10 = 5 1/2
9Y/ 10 = 11/2
Cross Multiply
9Y × 2 = 10 × 11
18Y = 110
Y = 110/18
Y = 6.1111111111 km/hr
Therefore, Kelli's can swim as fast as 6.11km/hr still in the water.
Ok so i only did 9-18
the circles are the questions and the answers are boxed in, sorry if they are not right i tried my best to help u out
4x - 5y + 20 = 0
<u> - 20 - 20</u>
4x - 5y = -20
4x - 4x - 5y = -20 - 4x
-5y = -20 - 4x
<u>-5y</u> = <u>-4x - 20</u>
-5 -5
y = ⁴/₅x + 4
The slope would be ⁴/₅.
6 - 3 = 3
-2 - (-9) = 7
(3 , 7)
