formula

$\begin{split} v_{Q} &= V_c \cdot \{\\ &{1\over2}cos(\phi_c-{\pi\over2}) &\cdots(6)\\ &+{1\over2}cos(2\omega_c t+\phi_c+{\pi\over2}) &\cdots(7)\\ &+{m\over4}cos((2\omega_c+\omega_s)t+\phi_c+\phi_s+{\pi\over2}) &\cdots(8)\\ &+{m\over4}cos((2\omega_c-\omega_s)t+\phi_c-\phi_s+{\pi\over2}) &\cdots(9)\\ &+{m\over2}cos(\omega_st+\phi_s)\cdot cos(\phi_c-{\pi\over2}) &\cdots(10)\\ \} \end{split}$