How would i go about sketching this...
Sketch y=log f(x)
when f(x) = 1 - ( x squared)
Can someone please talk me through the process...
The best way to do i think would be to use the composite function method. First draw y = f(x) = 1 - x
2. then draw y = log f(x) taking values on the horizontal axis as f(x). What i mean here is to draw u = 1 - x
2, and draw y = log u, taking the horizontal-axis in terms of 'u' values, and not 'x' values.
From this you can see that say when x = 0, u = 1. and you know from your graph of y = log u, that when u = 1, y = log u = log 1 = 0. So the output of the graph y = log f(x), at x = 0, would be y = 0.
Do this for some other values to get the shape of the graph. Also you know that log u, is only defined for u > 0. so that means that from the graph of u = 1 - x
2, that y = f(x) is only defined for -1 <x < 1.
Get it?