Mathématiques du secondaire qualifiant
Calcul trigonométrique (1_8)
Exercice 1 tp
Calculer
a = cos( |
23π |
+15π) |
4 |
b = sin(5π- |
3π |
) |
4 |
Correction
a = cos( |
23π |
+15π) = cos(π- |
3π |
) |
4 |
4 |
Donc a = -cos |
3π |
= - |
√(2) |
4 |
2 |
b = sin( 5π - |
3π |
) |
4 |
= sin(π- |
3π |
) |
4 |
donc b = sin |
3π |
= |
√(2) |
4 |
2 |
Exercice 2 tp
Calculer
cos²( |
7π |
+15π) + sin²(3π- |
3π |
) |
5 |
5 |
Exercice 3 tp
Calculer
Correction
a = cos( |
27π |
+ |
π |
) |
2 |
3 |
= cos( |
28π-π |
+ |
π |
) |
2 |
3 |
ou encore
= cos( |
-π |
+ 14π + |
π |
) |
2 |
3 |
= cos( |
-π |
+ |
π |
) |
2 |
3 |
= cos( |
π |
- |
π |
) |
2 |
3 |
Exercice 4 tp
Calculer
a = sin( |
5π |
- |
π |
) |
2 |
4 |
b = cos( |
5π |
+ |
π |
) |
2 |
3 |
Correction
a = sin( |
5π |
- |
π |
) |
2 |
4 |
= sin( |
4π+π |
- |
π |
) |
2 |
4 |
ou encore
a = sin( |
π |
+ 2π - |
π |
) |
2 |
4 |
= sin( |
π |
- |
π |
) |
2 |
4 |
donc, a = cos |
π |
= |
√(2) |
|
4 |
2 |
Ou encore
b = cos( |
4π+π |
+ |
π |
) |
2 |
3 |
= cos( |
π |
+ 2π + |
π |
) |
2 | 3 |
= cos( |
π |
+ |
π |
) |
2 |
3 |
donc b = -sin |
π |
= |
- √(3) |
|
3 |
2 |