QUADRATIC
FUNCTIONS
QUADRATIC FUNCTION
It is a second degree polynomial
Equation:
f(x) = ax2 + bx + c
where a, b, and c are real numbers
QUADRATIC FUNCTION
Vertex Form Equation:
f(x) = a(x – h)2 + k
where, a ≠ 0
QUADRATIC FUNCTION
Parabola
• It is the graph of the quadratic equation
QUADRATIC FUNCTION
If a > 0, the parabola opens upward
If a < 0, the parabola opens downward
y = a(x-h)2 + k
Vertex: (h,k)
Axis of Symmetry: x = h
GRAPHING A PARABOLA
WITH EQUATION IN VERTEX
FORM
To graph f(x) = a(x-h)2 + k
1. Determine whether the parabola opens upward or
downward. If a > 0, it opens upward. If a < 0, it opens
downward
2. Determine the vertex of the parabola. The vertex is (h,
k)
GRAPHING A PARABOLA
WITH EQUATION IN VERTEX
FORM
3. Find any x-intercept by replacing f(x) with 0. Solve
the resulting quadratic equation for x.
4. Find the y-intercept by replacing x with 0. Solve
the resulting equation for y.
5. Plot the intercepts and vertex. Connect these
points with a smooth curve
GRAPHING QUADRATIC
FUNCTIONS
1. Determine the coordinates of the vertex by finding
the x-coordinate from the formula x =
− b
2a
.
Substitute the x-coordinate into the original
quadratic function, and solve for y to determine
the y-coordinate for the vertex
GRAPHING QUADRATIC
FUNCTIONS
2. Determine a table of values by choosing at least
two x-values that are greater than the x-
coordinate of the vertex and two corresponding x-
values that are less than the x-coordinate of the
vertex
GRAPHING QUADRATIC
FUNCTIONS
3. Graph the function by plotting the vertex and the
set of ordered pairs from the table of values.
Next, connect the points with a smooth curve.
Mathematics 9 Lesson 3: Quadratic Functions

Mathematics 9 Lesson 3: Quadratic Functions

  • 1.
  • 2.
    QUADRATIC FUNCTION It isa second degree polynomial Equation: f(x) = ax2 + bx + c where a, b, and c are real numbers
  • 3.
    QUADRATIC FUNCTION Vertex FormEquation: f(x) = a(x – h)2 + k where, a ≠ 0
  • 4.
    QUADRATIC FUNCTION Parabola • Itis the graph of the quadratic equation
  • 5.
    QUADRATIC FUNCTION If a> 0, the parabola opens upward If a < 0, the parabola opens downward
  • 8.
    y = a(x-h)2+ k Vertex: (h,k) Axis of Symmetry: x = h
  • 9.
    GRAPHING A PARABOLA WITHEQUATION IN VERTEX FORM To graph f(x) = a(x-h)2 + k 1. Determine whether the parabola opens upward or downward. If a > 0, it opens upward. If a < 0, it opens downward 2. Determine the vertex of the parabola. The vertex is (h, k)
  • 10.
    GRAPHING A PARABOLA WITHEQUATION IN VERTEX FORM 3. Find any x-intercept by replacing f(x) with 0. Solve the resulting quadratic equation for x. 4. Find the y-intercept by replacing x with 0. Solve the resulting equation for y. 5. Plot the intercepts and vertex. Connect these points with a smooth curve
  • 11.
    GRAPHING QUADRATIC FUNCTIONS 1. Determinethe coordinates of the vertex by finding the x-coordinate from the formula x = − b 2a . Substitute the x-coordinate into the original quadratic function, and solve for y to determine the y-coordinate for the vertex
  • 12.
    GRAPHING QUADRATIC FUNCTIONS 2. Determinea table of values by choosing at least two x-values that are greater than the x- coordinate of the vertex and two corresponding x- values that are less than the x-coordinate of the vertex
  • 13.
    GRAPHING QUADRATIC FUNCTIONS 3. Graphthe function by plotting the vertex and the set of ordered pairs from the table of values. Next, connect the points with a smooth curve.