We want to satisfy
tan⁻¹ 0 = θ when 0° < θ < 90°.
The restriction on θ places the angle in the 1st quadrant.
When tan θ = 0, θ = 0°, 180°, 360°, ...
If θ >= 0, then a solution exists in the 1st quadrant.
Because of the requirement θ>0, no answer satisfies the given equation.
Answer: None
