### The Quadratic Formula - Identifying Coefficients

Check out Bas Rutten's Liver Shot on MMA Surge: http://bit.ly/MMASurgeEp1 Allison Moffett, host of the Mahalo Math Channel, uses her years of experience in the field of math education to help viewers learn how to identify the coefficients of a quadratic expression. Moffett gives two examples of finding the coefficients in a quadratic expression and stresses the importance of identifying the sign that goes with each coefficient. The Quadratic Formula: Identifying Coefficients --------------------------------------------------------------------- The quadratic formula is used to solve the quadratic expression and to do that you must learn to identify the?coefficients?in the formula. ?A quadratic expression may be given for the purpose of finding the roots of the equation.http://algebralab.org/lessons/lesson.aspx?file=algebra_quad_formula.xml??Knowing this will tell you where a parabola will touch or cross the x-axis.http://algebralab.org/lessons/lesson.aspx?file=algebra_quad_formula.xml??The quadratic formula depends on the two?coefficients?and the constant, and they have to be figured correctly or your overall calculation will be incorrect.http://www.youtube.com/watch?v=xEqNZOi1Ld8??Once the coeffecients are found, they can be plugged into the quadratic formula. The term quadratic comes from the Latin word?quadratus, which means "to make square".?? ?This term refers to the squaring that is done in the equation.http://www.math.toronto.edu/mathnet/questionCorner/quadorigin.html?? Step 1: ?Identify The?Coefficient?Positions --------------------------------------------------------------------- When looking at a?quadratic?expression, you must identify where each?coefficient?can be found. ?Take the equation: 2X^2+X-15=0. ?The "a"?coefficient?is always found?in front?of the X^2. ?The "b" coefficient is found in front of the x. ?The last coefficient, also called the constant or the free term, would be "c".http://www.youtube.com/watch?v=xEqNZOi1Ld8? ? Step 2: ?Write the Coefficients Out --------------------------------------------------------------------- When finding the coefficients in an expression, you will want to write them out, so will be able to access them when using the formula. ?In the example of 2X^2+X-15=0, you may write the coefficients out as a=2, b=1, c=-15. ?In this example, you cannot see a number in front of x; however, if x is there by itself, it is assumed that there is a one in front of it.http://www.youtube.com/watch?v=xEqNZOi1Ld8?? Step 3: ?Find Equation 2 Coefficients --------------------------------------------------------------------- Now look at the second example. ?The expression is written in the proper form and you can look for the numbers in front of the each x to find the coefficients. ?Once again, pay careful attention to the signs of the coefficients. ?Look in front of the coefficient to find the sign that needs to go with the number when you are writing it down. ?The equation is x^2-3x+5=0. ?In this example the x^2 does not have a coefficient in front of it, so a 1 is assumed. ?The coefficients in this example are a=1, b=-3, and c=5.http://www.youtube.com/watch?v=xEqNZOi1Ld8? Read more by visiting our page at: http://www.mahalo.com/the-quadratic-formula-identifying-coefficients/

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