In Roskam's book, we find the following relationship given for climb performance in jet aircraft:
Thrust requested = $D$ = $C_d \cdot (1/2 \cdot \rho \cdot V^2) \cdot S = C_d \cdot (1481.3 \cdot \delta \cdot M^2) \cdot S$
How can we show that $(1/2 \cdot \rho \cdot V^2)$ is equivalent to $(1481.3 \cdot \delta \cdot M^2)$?
Author: Jan Roskam
Title: Airplane Aerodynamics and Performance
Paragraph "9.2 CLIMB AND DRIFT-DOWN PERFORMANCE OF JET AIRPLANES"