Airy Bi
From specialfunctionswiki
The Airy functions $\mathrm{Ai}$ and $\mathrm{Bi}$ solve the differential equation $$y - xy = 0.$$
It can be shown that $$\mathrm{Ai}(x) = \dfrac{1}{\pi} \displaystyle\int_0^{\infty} \cos \left( \dfrac{t^3}{3} + xt \right) dt$$ and $$\mathrm{Bi}(x) = \dfrac{1}{\pi} \displaystyle\int_0^{\infty} \left[ e^{-\frac{t^3}{3} + xt} + \sin \left( \dfrac{t^3}{3}+xt \right) \right] dt.$$