A) 1
B) -1
C) \[\pm 1\]
D) \[\pm 2\]
Correct Answer: C
Solution :
[c] \[\underset{x\to 0}{\mathop{\lim }}\,kx\cos ecx=\underset{x\to 0}{\mathop{\lim }}\,x\cos eckx\] \[\Rightarrow k.\underset{x\to 0}{\mathop{\lim }}\,\frac{x}{\sin x}=\frac{1}{k}\underset{x\to 0}{\mathop{\lim }}\,\frac{kx}{\sin kx}\Rightarrow k=\frac{1}{k}\Rightarrow k=\pm 1.\]
You need to login to perform this action.
You will be redirected in
3 sec
