Question

The range of $f(x)={\sin }^{2}x-2\sin x$ is

• A. $(-\infty ,-1]$
• B. $[1,2]$
• C. $[-1,3]$
• D. $(1,2)$

Answer 1

Answer: (C)

${\sin }^{2}x-2\sin x+1-1={\left(\sin x-1\right)}^2-1\in \left[-1,3\right]$