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KCET2018MathematicsFunctions

Let f, g: R R be two functions defined as f(x)=|x|+x and g(x)=|x|-x x R . Then (f g)(x) for x < 0 is

Options

  1. A( 00 )
  2. B( 4 x )
  3. C( -4 x )
  4. D( 2 x )

Correct answer

C. ( -4 x )

Step-by-step solution

f(x)=|x|+xg(x)=|x|-xf[g(x)]=f[|x|-x]=|| x|-x|+|x|-x[x < 0]=|-2 x|+(-2 x)=-2 x-2 x=-4 x

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