# Limited Trigonometry- I

**Calculus**Level 4

\[f(x)=tan\left( \frac{x}{2} \right) \cdot sec \left( x \right)+tan\left( \frac{x}{2^2} \right) \cdot sec \left( \frac{x}{2} \right)+..+tan\left( \frac{x}{2^n} \right) \cdot sec \left( \frac{x}{2^{n-1}} \right)\] \[ g(x)=f(x)+tan\left( \frac{x}{2^n} \right) \]

where \(x \in \left( -\frac{\pi}{2} , \frac{\pi}{2} \right) \) and \(n \in \mathbb{N}\)

Evaluate the limit : \( \displaystyle \lim_{x \to 0} \left( \dfrac{g(x)}{x} \right)^{\frac{1}{x}}\)