1. The problem statement, all variables and given/known data The cosmic microwave background radiation has a blackbody type spectrum. Determine its max frequency and the correspondent wavelenght. Verify if found frequency is a microwave frequency and compare with the following curve: 2. Relevant equations Using the Wien Law displacemente, and knowing that CMBR has a thermal black body spectrum at a temperature of 2.725 K. We can easily calculate the wavelength peak and its frequency. λmax = 1,06mm frequency = λmax/c = 2,83E11HZ We can verify that the frequency that we obtained corresponds to the microwave frequency. But when i am comparing with this curve , i did not find any relation... I just do not know what is the relation of the graphic with the obtained results. Anybody to help? Help is always appreciated.!!!