Exercise Questions
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This exercise contains 11 questions. Use the Questions tab to view and track them.
Key Concepts
This exercise focuses on the following concepts:
A linear function has the form y=mx+c, where:
- m = slope (gradient) — measures steepness and direction
- c = y-intercept — where the line crosses the y-axis
The slope between two points (x1,y1) and (x2,y2) is: m=x2−x1y2−y1
Example: Sketch y=2x−3.
- Slope m=2 (rises 2 units for every 1 unit right)
- y-intercept: set x=0⇒y=−3, so point (0,−3)
- x-intercept: set y=0⇒x=1.5, so point (1.5,0)
A quadratic function has the form f(x)=ax2+bx+c.
- If a>0: parabola opens upward (minimum vertex)
- If a<0: parabola opens downward (maximum vertex)
The vertex is the turning point of the parabola:
xvertex=−2ab,yvertex=f(−2ab)
The axis of symmetry is the vertical line x=−2ab.
Example: Find the vertex of f(x)=x2−4x+3.
- a=1, b=−4
- x=−2(1)−4=2
- y=f(2)=4−8+3=−1
- Vertex: (2,−1)
| Intercept | Method |
|---|
| x-intercept(s) | Set y=0, solve for x (use quadratic formula if needed) |
| y-intercept | Set x=0, evaluate f(0) |
To solve f(x)=g(x) graphically:
- Plot both functions on the same axes.
- Identify the intersection points.
- The x-coordinates of these points are the solutions.
The function f(x)=a∣x−h∣+k produces a V-shaped graph:
- Vertex at (h,k)
- If a>0: V opens upward
- If a<0: V opens downward (inverted V)
Functions are used to model practical situations:
- Economic Equilibrium: Supply S(x) and demand D(x) functions intersect at the equilibrium point where supply equals demand.
- Projectile Motion: Height h(t)=−21gt2+v0t+h0 is a downward parabola; the vertex gives maximum height.
| Description | Formula |
|---|
| Slope-Intercept Form | y=mx+c |
| Slope Formula | m=x2−x1y2−y1 |
| Quadratic Standard Form | f(x)=ax2+bx+c |
| Axis of Symmetry | x=−2ab |
| Quadratic Formula | x=2a−b±b2−4ac |
| Vertex x-coordinate | x=2x1+x2 (midpoint of roots) |
Summary
This exercise focuses on the visual representation of algebraic functions on the Cartesian plane.
- Linear functions (y=mx+c) produce straight lines; identify slope and intercepts to sketch.
- Quadratic functions (f(x)=ax2+bx+c) produce parabolas; find vertex, axis of symmetry, and intercepts.
- Modulus functions (f(x)=a∣x∣+c) produce V-shapes; vertex and direction depend on a.
- Graphical solutions are found at intersection points of two curves.
- Real-world problems (equilibrium, projectile motion) are solved by identifying key graphical features.
Strategy: Always identify the function type first to predict the graph shape. For quadratics, find the vertex first as the central reference point.