Quadratic equations Questions and Answers
Math
Quadratic equationsFind the formula, in standard form y = ax² + bx+c, for a quadratic that has roots at x = -9 and x = 5, and has leading coefficient of 1.
y=
Math
Quadratic equationsA patient has an illness that typically lasts about 24 hours. The temperature, T, in degrees Fahrenheit, of the patient t hours after the illness begins is given by:
T(t) = -0.01t² +0.248t +97.2.
Use your calculator to graph the function and answer the following questions. Round all answers to 1 decimal place.
When does the patient's temperature reach it maximum value?
What is the patient's maximum temperature during the illness?
Math
Quadratic equationsWhich expression is the same as
x-12+3x²
3x² + x + 12
3x² + x - 12
-3x² + x + 12
3x² - x + 12
Math
Quadratic equationsSuppose the average number of vehicles arriving at the main gate of an amusement park is equal to 10 per minute, while the average number of average waiting time in minutes for each vehicle at the gate is given by f(x) =x-5/x²-10x, where x> 10.
(a) Estimate the admittance rate x that results in an average wait of 30 seconds.
(b) If one attendant can serve 4 vehicles per minute, how many attendants are needed to keep the average wait time 30 seconds or less?
(a) Estimate the admittance rate x that results in an average wait of 30 seconds.
The admittance is about vehicles per minute.
(Round to the nearest tenth as needed.)
Math
Quadratic equationsAfter using the discriminant on a quadratic, a student got a positive number. What can the student determine from this info
A The quadratic has one x- intercept.
B The quadratic has two - intercepts.
C The quadratic has no x-intercepts.
D Nothing can be determined with this information.
Math
Quadratic equationsSolve the following rational inequality x-6/x^2-64< 0.
State your answer using interval notation. Use U for union and oo for ∞.
Math
Quadratic equationsThe vertex form of the quadratic function f(x) = -7x² +28x - 23 is
ƒ (x) = a(x − h)² + k.
-
What is the value of a?
What is the value of h?
What is the value of k?
Math
Quadratic equationsGraph the equation y = -x² - 10x - 24 on the accompanying set of axes. You must
plot 5 points including the roots and the vertex.
Math
Quadratic equationsGiven the function f(x) = 3x² - 3x + 8. Calculate the following values:
f(− 2) =
f(− 1) =
f(0) =
f(1) =
f(2)=
Math
Quadratic equationsSolve the following equation using the quadratic formula.
2
4x = 2x + 3
The solution set is.
(Simplify your answer, including any radicals and i as needed. Use integers or fractions for any numbers in the expression. Use a comma to separate answers as needed.)
Math
Quadratic equationsThe following equation has two real solutions, one of which is zero.
9x² - 288x^3/4= 0
Find the other (non-zero) solution.
Give your answer as a simplified integer or improper fraction, if necessary. Do not type 'x= ' in your answer.
Math
Quadratic equationsA rocket is launched from a tower. The height of the rocket, y in feet, is related to the time after launch, x in seconds, by the given equation. Using this equation, find the time that the rocket will hit the ground, to the nearest 100th of second.
y=16x² +124x + 127
Math
Quadratic equationsSolve the following equation using the quadratic formula.
5x − 8x=4
*****
Points: 0 of 1
Next question
The solution set is.
(Simplify your answer, including any radicals and i as needed. Use integers or fractions for any numbers in the expression. Use a comma to separate answers as needed.)
Math
Quadratic equationsAdd. For answer, simplify numerator, but write denominator in factored form.
6T
5
8z+16
4
Math
Quadratic equationsSolve the equation for all values of x by completing the square.
x² - 16 = -6x
Math
Quadratic equationsSolve the equation using any method. Show your thinking. (2 poir
Explain why you chose that method using academic vocabulary. (
x² 22x + 121 = 16
02
-
Math
Quadratic equationsA population has a normal distribution. A sample of size n is selected from this population. Describe the shape of the sampling
distribution of the sample mean for the following case.
O The shape is skewed to the left.
O The shape is skewed to the right.
O The shape is normal.
n = 21
Math
Quadratic equationsThe height, in feet, of an object t seconds after being launched is given by the equation h = - 16t²+64t. How long does it take for the object to return to the ground?
a. 1 second
b. 2 seconds
c. 3 seconds
d. 4 seconds
e. 5 seconds
Math
Quadratic equationsIdentify the axis of symmetry, min/max value, and y-intercept.
y = x² +6x+16
Axis of Symmetry: x = - 3
Min Value = 7
y-intercept: 16
Axis of Symmetry: x = -7
Min Value =3
y-intercept: - 46
Axis of Symmetry: x = - 3
Min Value =7
y-intercept: -2
Axis of Symmetry: x = 4
Min Value =-6
y-intercept: - 22
There is no correct answer given.
Math
Quadratic equationsEarl's bike shop makes and sells bikes and has a profit function of P(x) = -2x² +260x-5000, where P(x) is the profit in dollars from selling x bikes
a) For this function P(30)= 1000. Explain what that means in the context of the situation. (4 pts)
b) According to this model, can the shop earn $5,000 in profit? Justify your answer. (4 pts)
c) How many bikes would the shop need to sell to break even? Round to the nearest whole number.(6pts)
Math
Quadratic equationsThe total fresh vegetables consumed per person per year can be modeled by
V(t) = 0.2(t- 3)2 + 64.8 where V(t) is the total fresh vegetables consumed per person in pounds per year t years since 2010.
Find when the minimum intake of fresh vegetables per person occurred? {final answer will be number only}
Math
Quadratic equationsA golf pro practices his swing by driving golf balls off the edge of a cliff into a lake. The height of the ball above the lake (measured in meters) as a function of time (measured in seconds and represented by the variable t) from the instant of impact with the golf club is the following:
h(t) = 58.8 + 19.6t - 4.9t²
The expressions shown are equivalent:
-4.9t² + 19.6t + 58.8 standard form
-4.9(t-6) (t + 2) factored form
-4.9(t - 2)² + 78.4 vertex form
1. Which expression is the most useful for finding how many seconds it takes for the ball to hit the water? Why?
2. Which expression is the most useful for finding how many seconds it takes for the ball to reach its maximum height? Why?
3. Which expression is the most useful for finding the maximum height of the ball? Justify your answer.
Math
Quadratic equationsFor the quadratic y = −3(x - 1)² + 2, the 2nd differences would be
-6
cannot be determined
2
-3
Math
Quadratic equationsIn an archer shoos an arrow straight upward with initial velocity of 80 ft/sec from a height of 4 feet then it's height above the ground in feet at time t in seconds is given the function:
h(t) = -8t² + 80t + 4
a. What is the maximum height reached by the arrow?
b. How long does it take for the arrow to reach the ground?
Math
Quadratic equationsFind the zeros of the function f(x) = -1.6x² + 19x - 53.1. Round values to the nearest hundredth (if necessary).
Math
Quadratic equationsSupposed Aven drops a ball off the top of a 10 foot pool slide, and
the ball follows the projectile h(t) = -16t² + 6, where t is the time in
seconds, and h is the height of the ball. Her friend Riley needs to
catch the ball between 2 feet and 5 feet off the top of the water.
Between what two times should Riley try to catch the ball? *
2 sec and 5 seconds
0.25 sec and 0.5 sec
0.83 sec and 0.94 sec
1.4 sec and 3.2 sec
Math
Quadratic equations(2 points each) Guadalupe stands on a platform and tosses a penny in the air. Its height in feet off the ground is h. Its time in seconds in the air is t. The equation is h = -16t² + 112t + 128.
a) How high is the penny after 2 seconds?
b) How long will it take for the penny to hit the ground?
Math
Quadratic equationsA diver jumps upward from the diving board and performs a double twist before entering the water.
The function shown describes her height h(t) in feet above the water, t seconds after she jumps.
h(t) = 10 + 40t - 16t²
Question: When will she be 26 feet above the water?
Math
Quadratic equationsA company sells widgets. The amount of profit, y, made by the company, is related to
the selling price of each widget, x, by the given equation. Using this equation, find out
what price the widgets should be sold for, to the nearest cent, for the company to
make the maximum profit.
y = -34x² + 1542x - 10037
Math
Quadratic equationsA company sells widgets. The amount of profit, y, made by the company, is related to the selling price of each widget, x, by the given equation. Using this equation, find out the maximum amount of profit the company can make, to the nearest dollar.
y=-6x²+600-5726
Math
Quadratic equationsSuppose that a ball is thrown from the top of a 104-foot building. The function
h(t) = - 16t2 +88t + 104 models the height in feet, h, of the ball t seconds after it is thrown.
a) When does the ball hit the ground?
The ball hits the ground after Select an answer ✓
b) Find the time(s) the ball will be 200 feet above ground. (You may use fractions or decimals. Use a comma to separate values, if necessary}
The ball is 200 feet above ground after Select an answer ✓
c) The ball will be at its highest point after t = 2.75 seconds. Find the height of the ball at that time.
The height of the ball after 2.75 seconds is Select an answer ✓
Math
Quadratic equationsSuppose that a roll of toilet paper is thrown upward from the top of a 52-foot building with initial velocity of 96 feet per second. The function h(t) 16t2 +96t+52 models the height in feet, h, of the toilet paper roll t seconds after it is thrown.
a) Determine the height of the toilet paper roll after 3 seconds.
After 3 seconds, the toilet paper roll is Select an answer above the ground.
b) When does the toilet paper roll hit the ground?
The toilet paper roll hits the ground after Select an answer
c) Determine when the toilet paper roll reaches 52 feet above the ground.
The toilet paper roll will reach 52 feet at Select an answer
Math
Quadratic equationsA toy rocket launch can be represented by a parabolic function. Your most recent
launch for the science fair can be modeled by the function
y = -4(x - 5)² + 125 where y is the height of the rocket and is the number
of seconds since launch. Graph this function and include all of the points listed
above, then discuss in context what the vertex and x-intercepts mean in context.
Math
Quadratic equationsFind the discriminant of each quadratic equation then
state the number and type of solutions.
-m² + 6m - 19 = -10
O 72; one real solution
O 0; two imaginary solutions
72; two real solutions
O 0; one real solution
O 0; two real solutions
Math
Quadratic equationsA ball is thrown into the air with an upward velocity of 48 ft/s. Its height h in feet after t seconds is given by the function h = -16t² + 48t + 8. In how many seconds does the ball reach its maximum height? Round to the nearest hundredth if necessary. What is the ball's maximum height?
Math
Quadratic equationsDetermine if the function is quadratic. If it is, determine if the graph is concave up or concave down. Determine if the vertex of the graph is a maximum point or a minimum point. y = 3x² + 2x+5
Is the function quadratic?
No Yes
Is the graph concave up or concave down?
Concave up Concave down
Is the vertex of the graph a maximum point or a minimum point?
Maximum point Minimum point
Math
Quadratic equationsFactor the four-term polynomial by grouping.
4x²-8xy-3x+6y
Select the correct choice below and, if necessary, fill in the answer box within your choice.
A.4x²-8xy-3x+6y=
B. The polynomial is not factorable by grouping.
Math
Quadratic equationsFactor the trinomial completely.
2x² +12x+10
Select the correct choice below and fill in any answer boxes within your choice.
O A. 2x² + 12x+10=(3)
(Factor completely)
O B. The polynomial is prime.
Math
Quadratic equationsWhich expression(s) is/are a quartic function? SELECT ALL THE APPLY.
ƒ(x) =−x (x + 1) (x − 5) (x+3)
f(x) =- (x + 9) (x + 1) (x − 5) (x+3)
f(x) = x³ - 0.15x+1
f(x) = x³
f(x)=x4-x²+2x–9
f(x) = 3x³ (x+2)
f(x) = 4x² + x +56
f (x) = -10x4
Math
Quadratic equationsFind the value of c that makes the expression a perfect square trinomial.
x² + 24x + c
a 144
b 12
c 36
d 576
Math
Quadratic equationsThe route that a trolley takes around a city can be represented by the functions x2 + y2 = 5. A train track's path can be described by the function 3x + y = 5. At which location(s) will the trolley and train meet?
O(1, 2) and (2, -1)
O(-1, 2) and (-2,-1)
O(2, -1) and (-2,-1)
O(-2, 1) and (-1,2)
Math
Quadratic equationsA rectangle has an area of 384 square meters. Its width is eight meters less than twice the
length. Let A be the area of the rectangle, L be the length and W be the width of the rectangle.
(A) Express the area A of the garden as a function of one of its dimensions. You may use either
the variable L or the variable W in your function, but you may not use both variables in the
function. (For example: A = L2-5L or A = W² + 5W are acceptable but not A = L* W)
Math
Quadratic equationsConsider the daily profit from the production and sale of x units of a product, given by
P(x) = -3600+400x - 4x² dollars.
a) Find the levels of production and sales that give a daily profit of $6000.
b) How many units need to be produced to maximize the profit?
Math
Quadratic equationsSolve the equation analytically for all complex solutions, giving exact forms in your solution set. Then, graph the left side of the equation as y, in the suggested viewing window and, using the capabilities of your calculator, support the real solutions.
x4-37x² +36=0: [-10,10] by [-100,100]
How many zeros are there?
The zeros are x=
(Use a comma to separate answers as needed.)
Math
Quadratic equationsGiven the quadratic equation
-3v² + 10 = -2v
Which of the following shows the equation in standard form, the value of the
discriminant, and the correct number and type of roots?
Standard Form: 3v²-2v-10-0
Discriminant: -84
2 Rational Roots
Standard Form: 3v² - 2v10 = 0
Discriminant: 124
2 Irrational Roots
Standard Form: 3v² - 2v 10 = 0
Discriminant: -84
2 Irrational Roots
Standard Form: 3v²-2v-10-0
Discriminant: -124
2 Complex Roots
Math
Quadratic equationsA smart-phone is thrown upwards from the top of a 240-foot building with an initial velocity of 32 feet per second. The height h of the smart-phone after t seconds is given by the quadratic equation h=16t² + 32t + 240. When will the smart-phone hit the ground?
Math
Quadratic equations1) Determine the equation of a quadratic function in standard form given zeros x = 5, x = -12 and point (0, -60).
2) Determine the equation of a quadratic function in standard form given zeros x = -4, x = -2 and point (-3,-1).