What are the characteristics of quadratic functions

Key Concepts

  • Define quadratic function.
  • Define quadratic parent function.
  • Draw the graph of 𝑓(𝑥)=𝑎x2.
  • Draw the graph of 𝑓(𝑥)=𝑎x2 when 𝑎<0.
  • Interpret quadratic functions from the table.
  • Compare the rate of change on the graph.

Exponential function 

An exponential function is the product of an initial amount and a constant ratio raised to a power.  

What are the characteristics of quadratic functions

Transformations of exponential functions 

Vertical translation of graphs 

Algebra: f(x) = ax+k

What are the characteristics of quadratic functions

Horizontal translation of graphs 

Algebra: f(x) = a(x−h)

What are the characteristics of quadratic functions

Polynomial 

A polynomial expression is an expression that has constants and variables by means of addition, multiplication, and exponentiation to a non-negative integer power. 

What are the characteristics of quadratic functions

Factorizing x2+bx+c = 0 

To the factor, a trinomial of the form x2+bx+c, find a factor pair of c that has a sum of b. Then use the factors you found to write the binomials that have a product equal to the trinomial.  

Quadratic function 

A function f defined by f(x) = ax2+bx+c, where a, b and c are real numbers and a≠0a≠0, is called a quadratic function

What are the characteristics of quadratic functions

Graph of a quadratic equation 

The graph of a quadratic function is a curve called a parabola. 

What are the characteristics of quadratic functions

  • The axis of symmetry intersects the vertex and divides the parabola in half.  
  • The vertex is the lowest (or highest) point on the graph of a quadratic function. 

Quadratic parent function 

The quadratic parent function is f(x) = x2. It is the simplest function in the quadratic function family. 

  • The quadratic parent function is f(x)=x2 
  • It is the simplest function in the quadratic function family. 

What are the characteristics of quadratic functions

Graph of f(x) = ax2

  • For 0<|a|<1, the shape of the parabola is wider than the parent function. 
  • For |a|>1, the shape of the parabola is narrower than the parent function. 

What are the characteristics of quadratic functions

Graph of f(x) = ax2 when a<0

  • f(x) = ax2 is the reflection of f(x) = -ax2 over the x-axis. 

What are the characteristics of quadratic functions

Compare the rate of change in the graph 

  • Find the slope of the line that passes through each pair of points. 
  • For positive intervals, the greater the value of a the greater the average rate of change. In this case, the ratio of the a-values in the two functions is the same as the ratio of the average rates of change. 

Exercise

1. How does the value of a in g(x) = -4x2 affect the graph when compared to the graph of the quadratic parent function?

2. In which interval is the function increasing?

What are the characteristics of quadratic functions

3. How does the value of a in h(x) = 0.15x2 affect the graph when compared to the graph of the quadratic parent function?

4. Write a quadratic equation for the area of the figure given. Find the area of the figure for the given value of x.

x=5

What are the characteristics of quadratic functions

Concept Map

A function 𝑓 defined by 𝑓(𝑥) = 𝑎𝑥2  + 𝑏𝑥 + 𝑐, where 𝑎, 𝑏, and 𝑐 are real numbers and 𝑎 ≠ 0, is called a quadratic function

The graph of a quadratic function is a curve called a parabola

What are the characteristics of quadratic functions

What we have learned

  • A function f defined by f(x) = ax2 + bx + c, where a, b, and c are real numbers and a≠0, is called a quadratic function.

What are the different types of quadratic functions?

1 Standard Form of Quadratic Function. The standard form of a quadratic function is f (x)=a (x-h) 2 +k, where (h,k) is the vertex of the parabola. 2 Domain and Range of Quadratic Function. ... 3 Graphing Quadratic Function. ... 4 Maxima and Minima of Quadratic Function. ... 5 Quadratic Functions Formula. ...

What are the characteristics of a quadratic function in vertex form?

Identifying Characteristics of Quadratic Functions in Vertex Form: y = a (x-p)^2 + q y = a(x−p)2 +q y = 2 {left ({x - 3} right)^2} - 8 y =2(x−3)2 −8 is a quadratic function in vertex form.

What are the 8 characteristics of a quadratic formula?

Eight Characteristics of Quadratic Formulas. The line of symmetry is always a vertical line of the form x = n, where n is a real number, and its axis of symmetry is the vertical line x =0. The x -intercepts are the points at which a parabola intersects the x -axis. These points are also known as zeroes, roots, solutions, and solution sets.

What is the standard form of a quadratic function?

A quadratic function can be in different forms: standard form, vertex form, and intercept form. Here are the general forms of each of them: Standard form: f (x) = ax 2 + bx + c, where a ≠ 0. Vertex form: f (x) = a (x - h) 2 + k, where a ≠ 0 and (h, k) is the vertex of the parabola representing the quadratic function.

What characteristic of a quadratic function is found in its standard form?

The quadratic function f(x) = a(x - h)2 + k, a not equal to zero, is said to be in standard form. If a is positive, the graph opens upward, and if a is negative, then it opens downward. The line of symmetry is the vertical line x = h, and the vertex is the point (h,k).

What are the characteristics of a quadratic graph?

The graph of a quadratic function is a U-shaped curve called a parabola. One important feature of the graph is that it has an extreme point, called the vertex. If the parabola opens up, the vertex represents the lowest point on the graph, or the minimum value of the quadratic function.

Which of the following is one of the characteristics of a quadratic equation?

The different characteristics of quadratic functions that are most commonly analyzed are the vertex (the maximum or minimum point), the x-intercepts (the zeros), and the axis of symmetry.

What are the 3 forms of quadratic functions?

There are three commonly-used forms of quadratics:.
Standard Form: y = a x 2 + b x + c y=ax^2+bx+c y=ax2+bx+c..
Factored Form: y = a ( x − r 1 ) ( x − r 2 ) y=a(x-r_1)(x-r_2) y=a(x−r1)(x−r2).
Vertex Form: y = a ( x − h ) 2 + k y=a(x-h)^2+k y=a(x−h)2+k..