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Unit 4 Quadratics. Quadratic Functions. Any function that can be written in the form. Put in Standard Form and Find a, b, and c. Is it quadratic?. Quadratic Functions. Graph forms a parabola concave up concave down. or. Determine whether a parabola opens up or down.
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Quadratic Functions • Any function that can be written in the form
Quadratic Functions • Graph forms a parabola concave up concave down or
Using a graphing calculator, find vertex, line of symmetry, max/min, and zeros and where the function increases and decreases..
To find the axis of symmetry • When
Vertex (h,k) form of a Quadratic • Standard Form:
Transformations • You can tell what the graph of the quadratic will look like if the eq. is in (h,k) form
Identifying Important Parts on Calculator • 2nd calc—then select max or min
Completing the Square • Used to go from standard form to (h,k) form or to get the equation in the form of a perfect square to solve • Steps: • Move the constant • Factor out the # in front of x2 • Take ½ of middle term and square it • Write in factored form for the perfect sq. trinomial • Add to both sides (multiply by # in front) • Move constant back to get in (h,k) form
Solving Quadratics • You can solve by graphing, factoring, square root method, and quadratic formula • Solutions, roots, or zeros
Solving by Graphing • Graph the parabola • Look for where is crosses the x-axis (where y=0) • May have 2 real, 1 real, or no real solutions (Show on calculator) Review finding the vertex
Solving Quadratics by Factoring • Factor the quadratic • Set each factor that contains a variable equal to zero and solve (zero product property)
Writing the Quadratic Eq. • Write the quadratic with the given roots of ½ and -5
Write the quadratic with • Roots of 2/3 and -2
More about solving • Graphing—not always best unless you have exact answers • Factoring—not every polynomial can be factored • Quadratic Formula—always works • Square Root method—may have to complete the square first
Solving using Quadratic formula • Must be in standard form • Identify a, b, and c
Discriminant • Used to identify the “type” of solutions you will have (without having to solve)
If the discriminant is… • A perfect square---2 rational solutions • A non-perfect square—2 irrational sol. • Zero—1 rational sol. • Negative—2 complex sol.