Mathematics

Problem

Let

f(x)=\dfrac{\sec x}{1+\tan x}

. Which of the following describes the domain of

f(x)

? a)

x\neq\left(2n+1\right)\dfrac{\pi}{2},\;n\in\mathbb{Z}

x\neq\left(2n+1\right)\dfrac{\pi}{2}\text{ and }\;x\neq-\dfrac{\pi}{4}+n\pi,\;n\in\mathbb{Z}

x\neq\left(2n+1\right)\dfrac{\pi}{2}\text{ and }x\neq\dfrac{\pi}{4}+n\pi,\;n\in\mathbb{Z}

x\neq-\dfrac{\pi}{4}+n\pi,\;n\in\mathbb{Z}