(ĐHQGHN-99) X COS3XCOS 3XK 62 KXĐS

bài 5: - GIAI DE THI LUONG GIAC
GIAI DE THI LUONG GIAC

Bài 5: (ĐHQGHN-99)

x cos3xcos 3xk 62

ĐS:

3  