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MATU • Trigonometria
MATU_TRI_069
Guía de ejercicios
Enunciado
Si $A $ y $ B $ son ángulos suplementarios, reducir:
$F = \frac{\text{sen}(2A + B) \tan(3B + 2A)}{\cot \left( \frac{A}{2} + \frac{3B}{2} \right) \cos \left( \frac{B}{2} + \frac{3A}{2} \right)}$
$F = \frac{\text{sen}(2A + B) \tan(3B + 2A)}{\cot \left( \frac{A}{2} + \frac{3B}{2} \right) \cos \left( \frac{B}{2} + \frac{3A}{2} \right)}$
Solución Paso a Paso
1. Datos del problema:
2. Fórmulas/Propiedades:
3. Desarrollo paso a paso:
1. $\text{sen}(2A+B) = \text{sen}(A + (A+B)) = \text{sen}(A + 180^\circ) = -\text{sen } A$
2. $\tan(3B+2A) = \tan(B + 2(B+A)) = \tan(B + 360^\circ) = \tan B$
3. $\cot(\frac{A+3B}{2}) = \cot(\frac{A+B+2B}{2}) = \cot(\frac{180^\circ+2B}{2}) = \cot(90^\circ+B) = -\tan B$
4. $\cos(\frac{B+3A}{2}) = \cos(\frac{B+A+2A}{2}) = \cos(\frac{180^\circ+2A}{2}) = \cos(90^\circ+A) = -\text{sen } A $
$$F = \frac{(-\text{sen } A)(\tan B)}{(-\tan B)(-\text{sen } A)} = \frac{-\text{sen } A \cdot \tan B}{\text{sen } A \cdot \tan B} = -1$$
4. Resultado final:
$$F = -1$$
- $A + B = \pi$ (o $180^\circ$)
2. Fórmulas/Propiedades:
- $\text{sen}(180^\circ + \theta) = -\text{sen } \theta$
- $\tan(360^\circ + \theta) = \tan \theta$
- $\cos(90^\circ + \theta) = -\text{sen } \theta$
- $\cot(90^\circ + \theta) = -\tan \theta$
3. Desarrollo paso a paso:
- Analizamos cada término usando $A+B = 180^\circ$:
1. $\text{sen}(2A+B) = \text{sen}(A + (A+B)) = \text{sen}(A + 180^\circ) = -\text{sen } A$
2. $\tan(3B+2A) = \tan(B + 2(B+A)) = \tan(B + 360^\circ) = \tan B$
3. $\cot(\frac{A+3B}{2}) = \cot(\frac{A+B+2B}{2}) = \cot(\frac{180^\circ+2B}{2}) = \cot(90^\circ+B) = -\tan B$
4. $\cos(\frac{B+3A}{2}) = \cos(\frac{B+A+2A}{2}) = \cos(\frac{180^\circ+2A}{2}) = \cos(90^\circ+A) = -\text{sen } A $
- Sustituimos en $ F $:
$$F = \frac{(-\text{sen } A)(\tan B)}{(-\tan B)(-\text{sen } A)} = \frac{-\text{sen } A \cdot \tan B}{\text{sen } A \cdot \tan B} = -1$$
4. Resultado final:
$$F = -1$$