DM TRIGONOMETRIE Attention, les réponses aux QCM de rattrapage ne rapportent que \( 25 \% \) des points. Soit \( A B C \) un triangle rectangle en \( A \) et \( \alpha=\widehat{A B C} \) Sachant que \( \sin (\alpha)=3 / 4 \) donner la valeur exacte de \( \tan (\alpha) \).

Prove that: \[ \frac{\cos \theta-\sin \theta}{\cos \theta+\sin \theta}=\sec 2 \theta-\tan 2 \]

\( a=7, b=5, c=3 \). Find \( \angle A \)

Define the tangent function using an example from a specific right triangle with known angles and side lengths.

23. El menor valor del ángulo \( x\left(0^{\circ} \leq x<180^{\circ}\right) \) que satisface la ecuación trigonométrica \( \cos ^{2}(x)-3 \cdot \operatorname{sen}^{2}(x)=0 \) es: A. \( 120^{\circ} \) B. \( 30^{\circ} \) C. \( 150^{\circ} \) D. \( 60^{\circ} \)

4. (s) Diben \( \operatorname{lan} \theta=-1.4826 \) dan \( 180^{\circ} \leq \theta \leq 360^{\circ} \) hilung sudul \( \theta \) Given than \( \tan \theta=-1.4826 \) ond \( 180^{\circ} \leq 0 \leq 360^{\circ} \). calculate angle \( \theta \)