Question

Which of the following functions is not defined at $x = 0$

• A. $\tanh x$
• B. $\text{cosech}x$
• C. $\sin x$
• D. $\sec ⥂ hx$

Answer 1

Answer: (B)

$\text{cosech}x$

Answer 2

$\text{cos} ⥂ \text{ech}x$is not defined at $x = 0$.