One form of the equation of a parabola is
y = ax² + bx + c
The curve passes through (0,-6), (-1,-12) and (3,0). Therefore
c = - 6 (1)
a - b + c = -12 (2)
9a + 3b + c = 0 (3)
Substitute (1) into (2) and into (3).
a - b -6 = -12
a - b = -6 (4)
9a + 3b - 6 = 0
9a + 3b = 6 (5)
Substitute a = b - 6 from (4) into (5).
9(b - 6) + 3b = 6
12b - 54 = 6
12b = 60
b = 5
a = b - 6 = -1
The equation is
y = -x² + 5x - 6
Let us use completing the square to write the equation in standard form for a parabola.
y = -[x² - 5x] - 6
= -[ (x - 2.5)² - 2.5²] - 6
= -(x - 2.5)² + 6.25 - 6
y = -(x - 2.5)² + 0.25
This is the standdard form of the equation for the parabola.
The vertex us at (2.5, 0.25).
The axis of symmetry is x = 2.5
Because the leading coefficient is -1 (negative), the curve opens downward.
The graph is shown below.
Answer: y = -(x - 2.5)² + 0.25
Answer:
4.8
Step-by-step explanation:
took test
Car A consumes 25 gallon and car B consumes 15 gallon.
Step-by-step explanation:
Given,
The fuel efficiency of car A = 20 miles per gallon.
The fuel efficiency of car B = 15 miles per gallon.
In a week, two cars went 725 miles and consumed 40 gallons.
To find the consumption of each car in that week.
Let,
Car A consumed x gallon
Car B consumed y gallon.
According to the problem,
x+y = 40 ----- (1)
20x+15y = 725
or, 4x+3y = 145 -------- (2)
From (1) we get, x = 40-y
Putting the value of x in (2) we get,
4(40-y)+3y = 145
or, 160-4y+3y = 145
or, -y = 145-160
or, y = 15
From (1) we get, x = 40-15 = 25
Hence,
Car A consumes 25 gallon and car B consumes 15 gallon.
Answer:
49.7%
Step-by-step explanation:
A cdircle is located within a square.
<u>Area of the circle</u>
Area = 
, where r = 4 units.
Area Circle = 50.3 units^2
<u>Area of the square</u>
Area = l*w or l^2 for a square, since l = w
Area = (10 units)^2
Area = 100 units^2
<u>Area in the square but outside the circle</u>
This is the difference [Square minus Circle Areas]
Square minus Circle Areas = 100 - 50.3 or <u>49.7 units^2</u>
<u>Probability</u>
The probability of picking a point in the square that is not in the circle is the ration of the two areas: <u>[Outside Circle/Square]x100%</u>
<u></u>
<u>(</u>49.7 units^2)/(100 units^2)x100% = 49.7%
<u></u>
Answer:
One-third
Step-by-step explanation:
One-third (which is about 33.3%) is greater than 25%