f(x)=(x-1)/(x+1)pzazz12 wrote:If f(x)=(x-1)/(x+1), then f(2x) is equal to
A. (3f(x)+1)/(f(x)+3)
B. (f(x)+1)/(f(x)+3)
C. (f(x)+3)/(f(x)+1)
D. (f(x)+3)/(f(x)+2)
E. None of these.
put x=1
f(1) = 0
put x=2
f(2) = 1/3
so, we should get 1/3 when we put x=1 in the options.
only A and B are left
put x=0, this should be same for f(x) and f(2x)
f(0) = -1
A gives -3+1 / -1+3 = -1 = f(x) = f(2x)
B gives 0
Hence pick A
Hope this helps!!
