If sec θ = cosec θ and 0° ≤ θ ≤ 90°, find the value of θ.

Given,

$\Rightarrow \text{sec θ = cosec θ} \\[1em] \Rightarrow \dfrac{1}{\text{cos θ}} = \dfrac{1}{\text{sin θ}} \\[1em] \Rightarrow \dfrac{\text{sin θ}}{\text{cos θ}} = 1 \\[1em] \Rightarrow \text{tan θ} = 1 \\[1em] \Rightarrow \text{tan θ = tan 45°} \\[1em] \Rightarrow \text{θ} = 45°.$

Hence, θ = 45°.