26
MCQ (Single Correct Answer)
Range of $f(x)=\frac{1}{1-2 \cos x}$ is
A
$\left[\frac{1}{3}, 1\right]$
B
$\left[-1, \frac{1}{3}\right]$
C
$(-\infty,-1] \cup\left[\frac{1}{3}, \infty\right)$
D
$\left[-\frac{1}{3}, 1\right]$
27
MCQ (Single Correct Answer)
Let $f(x)=\sqrt{1+x^2}$, then
A
$f(x y)=f(x) \cdot f(y)$
B
$f(x y) \geq f(x) \cdot f(y)$
C
$f(x y) \leq f(x) \cdot f(y)$
D
None of these
28
MCQ (Single Correct Answer)
Domain of $\sqrt{a^2-x^2}(a>0)$ is
A
$(-a, a)$
B
$[-a, a]$
C
$[0, a]$
D
$(-a, 0]$
29
MCQ (Single Correct Answer)
If $f(x)=a x+b$, where $a$ and $b$ are integers, $f(-1)=-5$ and $f(3)=3$, then $a$ and $b$ are equal to
A
$a=-3, b=-1$
B
$a=2, b=-3$
C
$a=0, b=2$
D
$a=2, b=3$
30
MCQ (Single Correct Answer)
The domain of the function $f$ defined by $f(x)=\sqrt{4-x}+\frac{1}{\sqrt{x^2-1}}$ is equal to
A
$(-\infty,-1) \cup(1,4]$
B
$(-\infty,-1] \cup(1,4]$
C
$(-\infty,-1) \cup[1,4]$
D
$(-\infty,-1) \cup[1,4)$