Describe the geometrical transformation that maps the graph of y=2^(4x) onto the graph of y=2^(4x-3)

  • 0 votes

I thought the answer would be [3,0] in a vector but on the mark scheme it says 'stretch in y direction, scale factor 1/8'.

does anyone know why?

Posted Sat 5th January, 2013 @ 23:16 by divya.k
Edited by divya.k on Sat 5th January, 2013 @ 23:21

1 Answer

  • 2 votes

Hi there, the reason why it's not a translation of (3,0) is because the x is a power which makes things more complicated. You need to treat y=2^(4x-3) as

y=   2^(4x) multiply 2^(-3)

which gives you y=2^(4x-3) when simplified.

This then gives you

y=  2^(4x) multiply 1/8

which is the same as y=(1/8)2^(4x)

And it is clear to see that the tranformation from the graph of y=2^(4x) to y=2^(4x-3) is a stretch in the y direction by a scale factor of 1/8.

Hope this clarifies everything for you :D

Answered Wed 16th January, 2013 @ 18:06 by Aimee