E_{φ} = \frac{E_{0}}{b} \exp (i ω t) \int_{0}^{b} \exp (- i k x \sin φ) d x

${E_\varphi = \frac{E_0}{b} \exp(i \omega t) \int_0^b \exp(-ikx \sin \varphi) \mathrm{d}x}$

Error