Functions Question 213
Question: If $ f(x)=ax+b $ and $ g(x)=cx+d $ , then $ f(g(x))=g(f(x)) $ is equivalent to
[UPSEAT 2001]
Options:
A) $ f(a)=g(c) $
B) $ f(b)=g(b) $
C) $ f(d)=g(b) $
D) $ f(c)=g(a) $
Show Answer
Answer:
Correct Answer: C
Solution:
We have $ f(x)=ax+b,,g(x)=cx+d $ and $ f(g(x))=g(f(x)) $
Þ $ f(cx+d)=g(ax+b) $
Þ $ a[cx+d]+b=c[ax+b]+d $
Þ $ ad+b=cb+d $
Þ $ f(d)=g(b) $ .
BETA
