| Hint | Answer | % Correct |
|---|---|---|
| cos(a+b) | cosacosb-sinasinb | 78%
|
| cos(a-b) | cosacosb+sinasinb | 78%
|
| sin(x/2) | +-sqrt((1-cosx^2)/2) | 78%
|
| cos(x/2) | +-sqrt((1+cosx^2)/2) | 78%
|
| sin(a+b) | sinacosb+cosasinb | 70%
|
| sin(a-b) | sinacosb-cosasinb | 70%
|
| sin2x | 2sinxcosx | 56%
|
| tan(a+b) | (tana+tanb)/(1-tanatanb) | 48%
|
| tan(a-b) | (tana-tanb)/(1+tanatanb) | 48%
|
| cos2x | cosx^2+sinx^2 | 37%
|
| cos2x | 1-2sinx^2 | 30%
|
| cos2x | 2cosx^2-1 | 30%
|
| tan(x/2) | +-sqrt((1-cosx)/(1+cosx)) | 30%
|
| tan(x/2) | (1-cosx)/(sinx) | 26%
|
| tan(x/2) | (sinx)/(1+cosx) | 26%
|
| tan2x | (2tanx)/(1-tanx^2) | 22%
|