Exō \( A B C \) est un triangle. On a \( A B=2 ; A C=4 \) et \( B C=2 \sqrt{5} \) ) calculer la ligne trigonométrique de \( A \hat{B C} \) 2)soit \( H \) le projete orthogonal de \( A \) sur \( (B C) \) calculer \( B H, A H \) Ex 4 ABC est un triangle reotangle en A . On a \( \sin \hat{B}=\frac{\sqrt{3}}{2} ; B C=6 \) ) calculer \( A B ; A C \) et déduire \( \cos \hat{B} \) et \( \tan \hat{B} \)

Find the period of the function \( y=2 \sin \left(2 x+\frac{\pi}{2}\right) \) Period

24) What is the period of the function : \( f(x)=\frac{-2}{3} \cos \left(\frac{\pi}{4}+4 x\right) \) a) \( 2 \pi \) b) \( \frac{3 \pi}{2} \) c) \( \pi \) d) \( \frac{\pi}{2} \)

15) Find the value of \( \sin \left(\frac{5 \pi}{3}\right) \) a) \( -\frac{\sqrt{3}}{2} \) b) \( \frac{1}{2} \) c) \( \frac{\sqrt{3}}{2} \) d) \( 0-\frac{1}{2} \)

19) Find \( \sin A \) and \( \cot B \) for a right triangle given that \( b=2, c=\sqrt{29} \). a) \( O \sin A=\frac{\sqrt{29}}{5}, \cot B=\frac{2}{5} \) b) \( \sin A=\frac{5 \sqrt{29}}{29}, \cot B=\frac{5}{2} \) c) \( O \sin A=\frac{2}{5}, \cot B=\frac{5}{2} \) d) \( O \sin A=\frac{5}{29}, \cot B=\frac{5}{2} \)

Find the height of a building that projects a shadow of 350 ft on the ground, If the angle of elevation fr the end of the shadow to the top of the building is \( 40^{\circ} \). a) 234 ft p) 294 ft b) 315 ft d) 302 ft