MCQ
The range of $\text{f(x)}=\cos[\text{x}],$ for $-\frac{\pi}{2}<\text{x}<\frac{\pi}{2}$ is:
  • A
    $\{-1,1,0\}$
  • B
    $\{\cos1,\cos2,1\}$
  • C
    {$\cos1,-\cos1,1$}
  • D
    $[-1,1]$

Answer

  1. $\{\cos1,\cos2,1\}$

Solution:

Since, $\text{f(x)}=\cos[\text{x}],$ where $\frac{-\pi}{2}<\text{x}<\frac{\pi}{2}$

$-\frac{\pi}{2}<\text{x}<\frac{\pi}{2}$

$\Rightarrow-1.57<\text{x}<1.57$

$\Rightarrow[\text{x}]\ \in\ \{-1,0,1,2\}$

Thus, $\cos[\text{x}]=\{\cos(-1),\cos0,\cos1,\cos2\}$

Range of $\text{f(x)}=\{\cos1,1,\cos2\}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free