Translations of Data and The Graph Scale-Change Theorem Sections 3.3 - 3.4 x1 = 36 Mean: 39.2 Median: 36 Mode: 36 Range: 24 IQR: 14 Variance: 81.198 Standard deviation: 9.011 x2=30 x3=40 x4= 54 x5=36 Mean: 64.2 Median: 61 Mode: 61 Range: 24 IQR: 14 Variance: 81.198 Standard deviation: 9.011 When there is a translation, the mean, median, and mode will be affected by the amount of the translation. The range, interquartile range, variance, and standard deviation remain unchanged with a translation; they are invariant under translation. Symmetries of Graphs! Reflection-symmetric - Line 180˚ Rotation-Symmetric or PointSymmetric – if it can be mapped to itself under a rotation of 180˚ around P Center of Symmetry: Point P. Power Function: f(x) = xn where n an integer ≥ 2 Examples! Symmetric to the x axis! Symmetric to the Y-axis! (x,y) then (-x,y) is also on The graph! Symmetric to the Origin! (x,y) then (-x,-y) is Also on the graph! Even functions symmetric to the y-axis! A function f is an even function if f ( x) f ( x) for all values of x in the domain of f. Example: f ( x) 3x 2 is even because f ( x) 3( x) 2 3x 2 f ( x) Odd functions – symmetric to the origin! A function f is an odd function if f ( x) f ( x) for all values of x in the domain of f. Example: f ( x) 5 x 3 x is odd because f ( x) 5( x)3 x 5x3 x (5x3 x) f ( x) Examples! Prove that the graph of y = x + x3 + 2x5 is symmetric to the origin. To prove, I must show that (a,b) then (-a, -b) If b = a + a3 + 2a5 , I must show that –b = -a + (-a3) + 2(-a)5 Multiply everything in the first by -1 -b = -1 (a + a3 + 2a5) -b = -1a + -a3 – 2a5 -b = -a +(-a)3 +2 (-a)5 Example! Use an automatic grapher to conjecture whether the function is odd, even, or neither. Then prove your conjecture. f(x) = 2x3 Looks odd! f(-x) = 2(-x)3 f(-x) = -2x3 Example Give equations for the asymptotes for so, x = -2 and y = 4 Homework Pages 183 – 184 1, 3-5, 8-13