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Quadratics, The Root Function & Inverses. GROUP 1 – Unit A Shehzaad, Henil , Nirojan , Umesh. Important Terminology. Expression : It is a mixture of numbers and variables that can be calculated. Ex: 4x²- 2x +6
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Quadratics, The Root Function & Inverses GROUP 1– Unit A Shehzaad, Henil, Nirojan, Umesh
Important Terminology Expression: It is a mixture of numbers and variables that can be calculated. Ex: 4x²- 2x +6 Equation: A statement where two expressions are supposed to equal each other. It relies on the value of the variables.Ex: 4x²- 2x +6= 0 Function: It is a relationship or expression involving one or more variables. For every (x) value there is only one unique, possible (y) value. Ex: y= 4x² -2x +6
Quadratic Equation A quadratic equation is an equation that contains x² as its highest degree or power. Base function is y= x²
Factoring & Solving Quadratic Equations Solving Quadratic Equations Factoring Quadratic Formula The equations must be in “standard form” in order to use any of the methods listed above Standard form: ax²+bx+c =0
Factoring Problems Fully factor each equation: 1) 5a2– 15a + 10 2) 3)
Discriminant Discriminant = b²-4acIt is a way to determine the number of possible solutions (or roots) of an equation. If b2– 4ac > 0 2 Distinct Real Roots If b2– 4ac = 0 2 Equal Real Roots If b2– 4ac< 0 NO Real Roots
Quadratic Formula After using the discriminant to find number of solutions, one must proceed to using the quadratic formula. Solve each equation using the quadratic formula: 1) 2)
Functions, Domain & Range Function: For every x value, there is only one y value. Vertical Line Test: a test which determines whether or not the equation is a function. Domain: It is the set of all first elements in a relation. The (x) values. For example: Range: The set of all second elements in a relation. The (y) values. For example: Function Notation y=f(x) For example: y=-2x+3 -> f(x) = -2x+3
Domain and Range What is the domain and range for the following functions: 1) 2)
Graphing Quadratic Functions Quadratic functions’ graph will always be a parabola. Vertex Form: y= a(x-h)² +k a> 0= minimum value of k when x is equal to h. a<0= maximum value of k when x is equal to h. *COMPLETE THE SQUARE*
Complete the Square Completing the square is simply finding the missing term in order to have a perfect square. Given a quadratic function, to put it in vertex form, follow the following steps: 1. Factor the coefficient of x2 from the terms in x2and x. Don’t do anything with the constant. 2. Complete the square on the terms in x2 and x as shown above. Since adding the missing term would change the given expression, we add it and subtract it at the same time. 3. The first three terms will be a perfect square. 4. Distribute the coefficient factored in step 1.
Complete the Square Example: y = x2 − 2x + 3 = x2 − 2x + 1 − 1 + 3 = x2 − 2x+ 1 − 1+ 3 = ( x − 1)2 + 2
Graphing Quadratic Functions Mapping Notation: Equation must be in vertex form. Create a new set of points to get the key points of the function. Graphing by Factoring: Equation must be in standard form. You must factor, in order to find the x and y intercept as well as the roots. Step Pattern:Equation must be in vertex form. Use the vertex and transformations to find points.
Inverses What is an inverse? An inverse is a relationship reflected through y=x An inverse has the same points in a graph but the x and y points are switched. Example (-2,4) would become (4,-2) Inverse Functions An inverse is not always a function. Inverse of a linear function will always be a function. Inverse of a quadratic function will never be a function. It is written as f¯¹(x).
Inverse Problems Find the inverse of each of the following: 1) 2)
Transformations Vertical Translations:y = f (x) + k • k > 0, graph shifts upk units. • k < 0, graph shifts downk units. Horizontal Translations:y = f (x – h) • h > 0, graph shifts righth units. • h < 0, graph shifts lefth units.
Transformations Reflection on the x-axis y=-f(x)Multiply the y-values by -1 Reflection on the y-axis y=f(-x) Multiply the x-values by -1
Transformations Vertical Stretches y=af(x) a > 1 = compression | 0>a>1 = stretch Horizontal Stretches y= f [b(x)] Use reciprocal to find value of x (1/b) b > 1 = compression | 0>b>1 = stretch
Horizontal Transformations y= a f (b(x-h))+k • (a)= vertical stretch • (b)= horizontal stretch • (h)= horizontal translation • (k)= vertical translation
Root Function It is written as f(x) = x We can never square root a negative number, so therefore, x >0
Transformation Problems Graph each transformation: 1) 2)
Transformation Problems Create an equation from each graph: 1)