Transformation
- Think of points first then function (equation)
- Watch out when the compression is conducted after the translation
Linear Equation forms
- standard form: ax+by=c
- slope-intercept form: y=mx+b
- point-slope form:
- Difficulty:
- based on points/equation changed, figure out the new equation/points
- when using general (a, b) to represent the original point
- new point finding or new equation writing for graph inversed and then stretched
Test
- (4) Graphing: given y=f(x), draw transformed graph
- translation, reflection, compression/expansion, square root, reciprocal, absolute value
- (2) Given original point, find new point (x, y)
- (1) Transformation terminology
- Translation (shifts) is always at the last
- Vertical translation ? units up or down
- Horizontal translation ? units to the left or right
- reflection (flip) over/about y-axis, x-axis, y=x (inverse)
- stretches (dilatation)
- vertical or horizontal compression by a factor of <1
- vertical or horizontal expansion by a factor of >1
- (4) Graphing the square root, reciprocal or absolute value of a transformed function (2/3)
- (1) Write the equation of a transformed function given a graph (final step will suffice)
- (1) Consider domain & range of a transformed equation
Graphing
When graphing, draw the arrows in both ends
- When drawing and label the vertical and horizontal asymptotes (p not pronounced), extend the ends using the dotted lines
- Congruent: translation & reflection
- Square root transformation
- Combined transformation
When graphing
- Make sure you factor before the graphing
- and Y is isolated
- Transformation equation:
- h>0: right; h<0: left
- point (x, y) -> point
- point (x, y) -> point
- new point finding would require the above step
- Square root transformation
graphing - Sketch
the part on or above the x-axis - Invariant point at y=1, 0
- Sketch
- Pick additional points on original curve as needed and take square root; Connect
- h>0: right; h<0: left
Reciprocal transformation
- Graphing
. - Vertical asymptotes: find the x-int of
and draw vertical asymptotes at the points - Horizontal asymptotes
- Invariant point at y=1, -1
- Pick additional points on original curve as needed and take reciprocal; Connect
- Vertical translation will lead to the shift of the horizontal asymptote
- Absolute value transformation
- Origin - the common point of x-axis and y-axis