Let \( f:\left[-\dfrac{\pi}{2}, \dfrac{\pi}{2}\right] \to \mathbb{R} \) be a continuous function such that \( f(0)=1 \) and \( \displaystyle \int_{0}^\dfrac{\pi}{3} f(t)\,dt = 0 \). Then which of the following statements is (are) TRUE?
The equation \( f(x) - 3\cos 3x = 0 \) has at least one solution in \( \left(0, \dfrac{\pi}{3}\right) \).
The equation \( f(x) - 3\sin 3x = -\dfrac{6}{\pi} \) has at least one solution in \( \left(0, \dfrac{\pi}{3}\right) \).
\(\displaystyle \lim_{x \to 0} \frac{x \int_{0}^{x} f(t)dt}{1 - e^{x^2}} = -1 \)
\( \displaystyle \lim_{x \to 0} \frac{\sin x \int_{0}^{x} f(t)dt}{x^2} = -1 \)