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If the equation of the parabola is represented byy = ax^2 + bx + c then it crosses the x-axis twice if and only if b^2 > 4ac

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Q: When does a parabola always cross the x-axis twice?
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Cylinder-A solid with two congruent circular bases that lie in parallel planes. 27. Data-Information, facts, or numbers that describe something. 28. Decimal-A number written using the base-ten place value system where it separates the ones' and tenths' digit. 29. Degrees-Unit of measure for angles. 30.Denominator-The number b in the fraction a/b where b cannot = 0. (show example) 31. Diagonal-A segment, other than a side, that connects two nonconsecutive vertices of a polygon. 32.Diameter-The distance across the circle through its center. 33.Difference-The result when one number is subtracted from another. 34. Discriminant-The expression under the radical (square root) in the quadratic formula (b^2 - 4ac) which helps to determine the number of solutions of a quadratic equations. (show on board) 35.Distance Formula-- used to calculate the length from one point in a coordinate plane to another. (show on board) 36.Distributive Property-For all numbers a, b, and c, a(b + c) = ab + ac.(show on board) 37. Domain of a function-The set of all input values for the function. The x values. 38. Equation-A mathematical sentence formed by setting two expressions equal to each other. 39. Equilateral triangle-A triangle with three congruent sides. 40. Evaluate-To find the value of an algebraic expression by substituting a number for each variable and performing the operation(s). 41. Exponent-A number that represents how many times a base is used as a factor in a repeated multiplication. (show on board) 42. Experimental Probability-A probability based on repeated trials of testing. What actually happens when you play the games. 43. Expression-a mathematical statement without an equal sign or an inequality symbol that includes at least one variable 44. Factor- A whole number or pair of whole numbers that multiply to be another number. 45.Fraction-A number of the form a/b where b cannot = 0. 46.Function-A set of rules including a domain which contains the inputs and a range which contains the outputs. For each input there is exactly one output. 47.GCF-The greatest whole number that is a factor of two or more nonzero whole numbers. 48.Heptagon-A polygon with 7 sides. 49.Hexagon-A polygon with 6 sides. 50.Histogram-A graph that displays data from a frequency table. 51. Horizontal-a line or a direction that is parallel to the x-axis and goes from left to right (from East to West) 52.Hypotenuse-The side of a right triangle that is opposite the right angle. Always the longest side of a right triangle. 53.Image-The new figure formed by a transformation. After the transformation. 54.Improper Fraction-A fraction whose numerator is greater than or equal to its denominator. 55.Inequality-A mathematical sentence formed by placing one of the symbols <,>,≤, or ≥ between two expressions. 56. Input-The number that is put into the function. Set of all of these forms the domain. 57.Integers-The set of numbers…-4, -3, -2, -1, 0, 1, 2, 3, 4. Also referred to as the whole numbers and their opposites. 58.Interquartile Range-The difference of the upper and lower quartiles of a data set. 59. Intersection-the set of points or a point that two geometric figures have in common. 60. Inverse operations-Operations that "undo" each other. 61. Irrational Number-A real number that cannot be written as a quotient of two integers. The decimal form of this set of numbers neither terminates nor repeats. 62. Isosceles Triangle-A triangle with at least two congruent sides. 63. LCD-The least common multiple of the denominators of two or more fractions. 64. LCM-The least number that is a common multiple of two or more numbers. 65. Like Terms-Terms that have identical variable parts or are both constants. 66. Lower Quartile (Quartile 1)-The median of the lower half of an ordered data set 67. Mean-The sum of the values in a data set divided by the number of values. Also called the average. 68. Median-The middle value in a data set when the values are written in numerical order. 69. Midpoint-The point of a line segment that is equidistant from the endpoints of the segment (in the middle). 70. Midpoint Formula-- Formula used to find the point in the middle of two other points. (show on board) 71. Mixed Number-A number that has a whole number part and a fraction part. 72. Mode-The value in a data set that occurs most often. 73. Monomial-Polynomial with one term 74. Multiplication Identity-Property that states any number times 1 will result in the same number. 75. Multiplicative Inverse-Property that states a number multiplied by its inverse results in 1. A number and its reciprocal. 76. Natural Numbers-The set of numbers 1,2,3,4,5,……. Also known as the counting numbers. 77. Numerator-The number a in the fraction a/b. The top of a fraction. 78. Obtuse Angle-An angle whose measure is between 90 and 180 degrees. 79. Obtuse Triangle-A triangle with one obtuse angle. 80. Octagon-A polygon with eight sides. 81. Opposites-Two numbers that are the same distance from 0 on a number line but are on different sides of 0. 82. Order of operations-A set of rules for evaluating an expression involving more than one operation. We can use PEMDAS to help us follow these rules. 83. Ordered Pair-A pair of coordinates (x and y) that can be used to represent a point in a coordinate plane. 84. Origin-The ordered pair (0,0) where the x-axis and the y-axis meet in a coordinate plane. 85. Outlier-A value that is widely separated from the rest of the data in a data set. 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Quadrant-One of the four regions that a coordinate plane is divided into by the x-axis and the y-axis. 108. Quadratic Equation-an equation that can be written in the standard form ax^2 + bx + c where the highest degree is 2. (show on board) 109. Quadratic Formula-A formula used to solve a quadratic equation. (show on board) 110. Quadrilateral-A geometric figure made up of four line segments, called sides, that intersect only at their endpoints; a polygon with four sides. 111. Quotient-The result of a division problem. 112. Radical- Another name for a square root. 113. . Radicand-The number or expression inside a radical (square root) symbol. (Show on board) 114. Radius of a Circle-The distance between the center and any point on the circle. 115. Range-The set of numbers of a function that contains all the output values. 116. Rate-A ratio of two quantities measured in different units. 117. Ratio-A comparison of two numbers using division. 118. Rational Number-A number that can be written as a fraction (a/b). 119. Ray-A part of a line that begins at a point (initial point) and extends in one direction without end. 120. Real Numbers-The set of all rational numbers and irrational numbers. All numbers on the the number line. 121. Reciprocals-Two nonzero numbers whose product is 1. When you "flip" a fraction. 122. Reflection-A transformation that flips a figure in a line, creating a mirror image of the figure. 123. Regular Polygon-A polygon with all sides equal in length and all angles equal in measure. A polygon that is both equilateral and equiangular. 124. Rhombus-A parallelogram with four congruent sides. 125. Right Angle-An angle whose measure is exactly 90 degrees. 126. Right Triangle-A triangle with one right angle. 127. Rotation-A transformation that turns/spins a figure through a given angle. 128. Scalene Triangle-A triangle with no congruent sides. 129. Scatter Plot-The graph of a set of a data pair which is a collection of points in a coordinate plane. 130. Scientific Notation-A number of the form c X 10n where c is greater than or equal to 1 and less than 10 and n is not an integer. (show on board) 131. Similar Polygons-Polygons that have the same shape but not necessarily the same size. 132. Simplify-To reduce or breakdown an expression into its lowest terms possible. 133. Slope-The ratio of a line's vertical change to its horizontal change between any two points. The rate of change of a line. Represented by the letter m. Rise over run. 134. Slope Formula-Formula used to find the rate of change of a line. (Show on board) 135. Slope-Intercept Form-A linear equation written in the form y=mx+b where m is the slope and b is the y-intercept of the equation's graph. (show on board) 136. Solution-A number or ordered pair of numbers that make an equation or an inequality true 137. Solve-To find the value of the variable(s) of an equation or inequality. 138. Sphere-A solid formed by all points in space that are the same distance from a fixed point called the center. 139. Square Root-Also called a radical. When trying to fine what number squared gives you the number inside this symbol. (show symbol on board) 140. Stem-and-Leaf Plots-A data display that helps you see how data values are distributed. Each data value is separated into the last digit and the remaining digits. 141. Straight Angle-An angle whose measure is exactly 180 degrees. 142. Substitution-A property that allows you to replace terms of equal value for one another. Example: putting 4 in for x. 143. Sum-The result when two or more numbers are added. 144. Supplementary Angles-Two angles whose measures have a sum of 180 degrees. 145. Surface Area-The sum of the areas of the outside surfaces of a solid. 146. Terminating Decimal-A decimal that has a final digit that stops and does not repeat. 147. Theoretical Probability-The probability of an event when all outcomes are equally likely. What is supposed to happen when playing the game. 148. Transformation-A movement of a figure in a plane that is done by a reflection, rotation, translation, or dilation. 149. Translation-A transformation that slides each point of a figure the same distance in the same direction. 150. Trapezoid-A quadrilateral with exactly one pair of opposite side parallel. 151. Trinomial-A polynomial with three terms. 152. Unit Rate-A rate that has a denominator of 1 unit. 153. Upper Quartile (Quartile 3)-The median of the upper half of an ordered data set 154. Variable-A letter that is used to represent one or more numbers. 155. Vertex-The common endpoint of the two rays that form an angle. Where the endpoints of polygons meet. 156. Vertical Angles-A pair of opposite angles formed when two lines meet at a common point. 157. Vertical-A line or direction that is parallel to the y-axis and goes from top to bottom/up and down (north to south) 158. Volume-The amount of space a solid contains in terms of cubic units. Amount of space inside the object. 159. Whole Numbers-The set of numbers 0,1,2,3….. Also called the Natural numbers including 0. 160. X-Axis-The horizontal axis in a coordinate plane. 161. X-Coordinate-The first number in an ordered pair representing a point in a coordinate plane. 162. X-Intercept-The x-coordinate of a point where the graph crosses the xaxis when y=0. 163. Y-Axis-The vertical axis in a coordinate plane.