methods / transformations.mdon commit methods transformations - f(x) (6af190c)
   1# Transformation
   2
   3**Order of operations:** DRT - Dilations, Reflections, Translations
   4
   5## $f(x) = x^n$ to $f(x)=a(x-h)^n+K$##
   6
   7- $|a|$ is the dilation factor of $|a|$ units parallel to $y$-axis or from $x$-axis
   8- if $a<0$, graph is reflected over $x$-axis
   9- $k$ - translation of $k$ units parallel to $y$-axis or from $x$-axis
  10- $h$ - translation of $h$ units parallel to $x$-axis or from $y$-axis
  11
  12## Translations
  13
  14For $y = f(x)$, these processes are equivalent:
  15
  16- applying the translation $(x, y) \rightarrow (x + h, y + k)$ to the graph of $y = f$(x)$
  17- replacing $x$ with $x − h$ and $y$ with $y − k$ to obtain $y − k = f (x − h)$
  18
  19## Dilations
  20
  21For the graph of $y = f(x)$, there are two pairs of equivalent processes:
  22
  231. - Dilating from $x$-axis: $(x, y) \rightarrow (x, by)$
  24   - Replacing $y$ with $y \over b$ to obtain $y = b f(x)$
  25
  262. - Dilating from $y$-axis: $(x, y) \rightarrow (ax, y)$
  27   - Replacing $x$ with $x \over a$ to obtain $y = f({x \over a})$
  28
  29For graph of $y={1 \over x}$, horizontal & vertical dilations are equivalent (symmetrical). If $y={a \over x}$, graph is contracted rather than dilated.
  30
  31## Transformations from $f(x)$ to $y=Af[n(x+c)]+b$#
  32
  33Applies to exponential, log, trig, power, polynomial functions.  
  34Functions must be written in form $y=Af[n(x+c)] + b$
  35
  36$A$ - dilation by factor $A$ from $x$-axis (if $A<0$, reflection across $y$-axis)  
  37$n$ - dilation by factor $1 \over n$ from $y$-axis (if $n<0$, reflection across $x$-axis)  
  38$c$ - translation from $y$-axis ($x$-shift)  
  39$b$ - translation from $x$-axis ($y$-shift)