Rational functions

1103030902

Level: 
B
A part of the graph of the function \( f(x)=\frac4x \) is shown in the picture. Identify which of the following statements is true.
The function \( g \) defined by \( g(x)=\left|f(x)\right| \) is bounded below.
The function \( f \) is bounded below.
The function $h$ defined by \( h(x)=-f(x) \) is bounded below.
The function $m$ defined by \( m(x)=f(x)+4 \) is bounded below.

1103102304

Level: 
C
Function \( f \) is given completely by the graph. Which of the following statements is false?
\( f(x)=\frac{|x|}x,\ x\in[-5;0)\cup(0;5] \)
\( f(x)=\left|\frac{|x|}x\right|,\ x\in[-5;0)\cup(0;5] \)
\( f(x)=1,\ x\in[-5;0)\cup(0;5] \)
\( f(x)=\frac{x}x,\ x\in[-5;0)\cup(0;5] \)

1003028402

Level: 
C
Let \( f(x)=\frac{2x-4}{x^2-4} \). Which of the statements about the domain and the range of the function \( f \) is true?
\( -2\notin D(f) \wedge -2\in H(f) \)
\( -2\in D(f) \wedge -2\notin H(f) \)
\( -2\in D(f) \wedge -2\in H(f) \)
\( -2\notin D(f) \wedge -2\notin H(f) \)