Functions Question 411
Question: The domain for which the functions $ f(x)=2x^{2}-1 $ and $ g(x)=1-3x $ is equal, i.e., $ f(x)=g(x). $ , is
Options:
A) $ {0,2} $
B) $ { \frac{1}{2},-2 } $
C) $ { -\frac{1}{2},2 } $
D) $ { \frac{1}{2},2 } $
Show Answer
Answer:
Correct Answer: B
Solution:
[b] For $ f(x)=g(x)\Rightarrow 2x^{2}-1=1-3x $
$ \Rightarrow 2x^{2}+3x-2=0\Rightarrow 2x^{2}+4x-x-2=0 $
$ \Rightarrow 2x(x+2)-1(x+2)=0\Rightarrow (x+2)(2x-1)=0 $
$ \Rightarrow ,x=-2,\frac{1}{2} $
$ \therefore $ The domain for which the function $ f(x)=g(x) $ is $ { -2,,\frac{1}{2} }. $
BETA
