Two coherent sources emit light waves which superimpose at a point where these can be expressed as ${\mathrm{E}}_1={\mathrm{E}}_0\sin \left(\mathrm{\omega t}+\frac{\mathrm{\pi }}{4}\right),{\mathrm{E}}_2=2{\mathrm{E}}_0\sin (\mathrm{\omega t}-\mathrm{\pi }/4)$where ${\mathrm{E}}_1\text{ and }{\mathrm{E}}_2$ are the electric strengths of the two waves at the given point. If I is the intensity of the wave expressed by field strength E₁ find the resultant intensity