AS/A2 Pure 1 Pure 3

P2 Topic 2: Functions
Composition of functions 1
The functions f(x)=ax2+bx+c and g(x)=dx+e are displayed, together with the combined functions y=fg(x) and y=gf(x). Investigate the effect of changing a, b, c, d and e.
When - if ever - does fg(x)=gf(x)?

Based on free Java applets from JavaMath