90 likes | 168 Vues
Trig revision. End of year. Find the side. 8 2 + 15 2 = b 2 e 2 + 5 2 = 9 2 b = 17 e =7.5. Find the side.
E N D
Trig revision End of year
Find the side 82 + 152 = b2 e2 + 52 = 92 b = 17e =7.5
Find the side.... An aeroplane on a straight take-off path reaches a height of 1800m after covering a distance of 10km on the ground. What is the length of its take-off path to the nearest 0.1km? 88.6km
Find the side.... A tree casts a shadow 11 metres in length when the sun’s rays make an angle of 34 with the ground. How tall is the tree? tan 34° = x/11 x = 11tan 34° x x = 7.4 m 34° 11m
Find the side.... Romeo wants to climb to Juliet’s balcony which is 5.6 metres above the ground. How long a ladder must he get if he needs (for safety) to make an angle of 45°with the balcony? cos45°=5.6/x 5.6 m • xcos45°=5.6 45 • x =5.6/cos45° • x =7.9 m
Find the angle.... Juliet’s friendalso tries to reach the balcony but can only find a ladder 7.6 metres long. Is she able to climb to the balcony if she must have the an angle of more than 40°? cosθ = 5.6/7.6 θ = cos-1(5.6/7.6) 5.6 m θ θ = 42.5° yes, she is able to climb!
Find the angle.... The Eiffel tower is 300 metres tall. When it casts a shadow of 173.2 metres along the ground, what angle are the sun’s rays making with the ground? tanθ = 300/173.2 θ = tan-1(300/173.2) θ = 60° θ
N Each day, the lifeguards at the Surf Club do a training run and swim. They start at point A close to the water and run 400 m due East to a point B. They swim out to a buoy C directly north of B and 260 m away before returning back to the beach. What is the bearing of the buoy from the starting point? Give your answer to the nearest degree N tanθ = 260/400 θ = tan-1(260/400) 260m θ = 33° 57° θ 400m Bearing is 057°
The site next to Sarah's family site has a gazebo erected on it. The gazebo is made up of 4 poles each 2 m in height on top of which another set of poles from a square pyramid. The pyramid is 2.4m square and the poles which form the peak of the gazebo are all 1.8 m in length. • Find the height of the gazebo at its highest point.. 2.6m