Coherent light of frequency f travels in air and is incident on two narrow slits. The interference pattern is observed on a distant screen that is directly opposite the slits. The frequency of light f can be varied. For f=5.60×1012Hz there is an interference maximum for θ=60.0∘. The next higher frequency for which there is an interference maximum at this angle is 7.47×1012Hz. What is the separation d between the two slits?