A+B |
2 |
A?B |
2 |
1?cos(A+B) |
2 |
1+cos(A?B) |
2 |
4?3cos(A+B)+cos(A?B) |
2 |
∴4-3cos(A+B)+cos(A-B)=4,即3cos(A+B)=cos(A-B),
∴3cosAcosB-3sinAsinB=cosAcosB+sinAsinB,即2cosAcosB=4sinAsinB,
則tanAtanB=
sinAsinB |
cosAcosB |
2 |
4 |
1 |
2 |
故答案為:
1 |
2 |
A+B |
2 |
A?B |
2 |
A+B |
2 |
A?B |
2 |
1?cos(A+B) |
2 |
1+cos(A?B) |
2 |
4?3cos(A+B)+cos(A?B) |
2 |
sinAsinB |
cosAcosB |
2 |
4 |
1 |
2 |
1 |
2 |