Open
the applet: Compare the meaning of the parameters b and c
in the two functions
f1(x) = sin (bx - c) and f2(x) = sin[b(x – c)]. Note:
The applet uses radian angle measure!
We start with c = 0, so the graphs are the same, i.e. y =
sin bx. Change b - what is the influence of b?
Now reset b to 1 and keep it at 1, so the graphs are the same,
i.e. y = sin (x – c). Change c ... What happens?
Now what happens when b and c both change?
Now change b to 2 and keep it constant. Then change c ...
Now change b to 3. Then change c ...
Now change b to 0,5. Then change c ...
Describe the differences in the way f1(x) and f2(x) behave.
Which form of the formula is more useful? Why?
Draw
the graphs of y = sin (2x – 3) and y = sin 2[(x –
3)] and check it in the applet.
|