Question

Which of the following is incorrect?

Options

• \[\sin x = - \frac{1}{5}\]

   

• cos x = 1

• \[\sec x = \frac{1}{2}\]

   

• tan x = 20

Answer 1

`bb(sec x = 1/2)`

Explanation:

\[\sin x = - \frac{1}{5}\] is correct as \[- 1 \leq \sin x \leq 1\]

cos x = 1 is correct as cos x = 1 is correct as

\[\sec x = \frac{1}{2}\] is not correct as \[\sec x \in ( - \infty , - 1] \cup [1, \infty )\]

tan x = 20 is correct as tan x can take any real value.

Hence, the correct answer is option \[\sec x = \frac{1}{2}\].