Upload
others
View
1
Download
0
Embed Size (px)
Citation preview
Name: ______________________________________ Date: ________________
Graphing Quadratics in Standard Form Study Guide
For this assessment, you will need to know how to find the following from an equation:
• Concavity (up or down)
• Vertex
• Axis of symmetry
• Y-‐intercept
• X-‐intercept(s)
• Other point on the graph
• Domain
• Range
Reminders:
• If the value of a is positive, the graph concaves up. If the value of a is
negative, the graph concaves down.
• The vertex is the point on the graph that is the maximum or minimum point.
To find the x of the vertex, use the equation 𝑥 = − !!!
• To find the y of the vertex, substitute the x into the equation and solve for y.
• The axis of symmetry is 𝑥 = − !!! (the x coordinate of the vertex)
• The y intercept is 0, 𝑐
• To find the x-‐intercept(s), let y=0 and solve for x (to solve for x, you will need
to solve the quadratic equation by the appropriate method-‐ extract the root,
zero product property, complete the square, quadratic formula)
• To find another point on the graph, substitute a value in for x and solve for y.
• Domain is ALWAYS 𝑥 ∈ (−∞,∞)
• Range is the set of y values (look at the y value of the vertex and look at the
concavity to find the range)
Directions: For each equation, find the concavity, vertex, axis of symmetry, x-‐intercept(s), y-‐intercept, domain and range. Then, graph the parabola. 1. 𝒚 = 𝒙𝟐 + 𝟐𝒙+ 𝟏 Concavity: Vertex: Axis of symmetry: X-‐intercept(s): Y-‐intercept: Other point on the graph: Domain: Range: Graph:
2. 𝒚 = 𝒙𝟐 − 𝟗 Concavity: Vertex: Axis of symmetry: X-‐intercept(s): Y-‐intercept: Other point on the graph: Domain: Range: Graph:
3. 𝒚 = −𝟔𝒙𝟐 − 𝟒𝒙− 𝟓 Concavity: Vertex: Axis of symmetry: X-‐intercept(s): Y-‐intercept: Other point on the graph: Domain: Range: Graph:
4. 𝒚 = −𝒙𝟐 + 𝟐𝒙 Concavity: Vertex: Axis of symmetry: X-‐intercept(s): Y-‐intercept: Other point on the graph: Domain: Range: Graph:
Answer Key
1. • Concavity: up • Vertex: (−1,0) • Axis of symmetry: 𝑥 = −1 • X-‐intercept(s):(−1, 0) • Y-‐intercept: (0, 1) • Other point: will vary • Domain: 𝑥 ∈ (−∞,∞)
Range: 𝑦 ∈ [0,∞) • Graph:
2. • Concavity: up • Vertex: (0,−9) • Axis of symmetry: 𝑥 = 0 • X-‐intercept(s):
3, 0 𝑎𝑛𝑑 (−3,0) • Y-‐intercept: (0,−9) • Other point: will vary • Domain: 𝑥 ∈ (−∞,∞)
Range: 𝑦 ∈ [−9,∞) • Graph:
3. • Concavity: down • Vertex: (− !
!,− !"
!)
• Axis of symmetry: 𝑥 = − !!
• X-‐intercept(s): none • Y-‐intercept: (0,−5) • Other point: will vary • Domain: 𝑥 ∈ (−∞,∞)
Range: 𝑦 ∈ (−∞,− !"!]
• Graph: 4.
• Concavity: down • Vertex: (1, 1) • Axis of symmetry: 𝑥 = 1 • X-‐intercept(s): 0, 0 𝑎𝑛𝑑 (2, 0) • Y-‐intercept: (0, 0) • Other point: will vary • Domain: 𝑥 ∈ (−∞,∞)
Range: 𝑦 ∈ (−∞, 1] • Graph: