Question

If $li{m}_{x\to 0}$kx cosec x = $li{m}_{x\to 0}$x cosec kx , then k =

• A. 1
• B. -1
• C.
• D.

Answer 1

The correct option is C

$li{m}_{x\to 0}$kx cosec x = $li{m}_{x\to 0}$ x cosec kx

= k $li{m}_{x\to 0}$$\frac{x}{sinx}$ =$\frac{1}{k}$$li{m}_{x\to 0}$$\frac{kx}{sinkx}$ =k=$\frac{1}{k}$=k=± 1