Planck's law was also stated above as a function of frequency. The intensity maximum for this is given by ν ν peak = T × × 5.879... × × 10 10 H z / K . In unitless form, the maximum occurs when e x ( 1 − − x / 3 ) = 1 , where x = h ν ν / k T . The approximate numerical solution is x ≈ ≈ 2.82 . At a typical room temperature of 293 K (20 °C), the maximum intensity is for ν ν = 17 THz.