hscishard
Active Member
Lol my stupid year 10 self thought that Excel Ext 2 book contained all the Topics for 4unit, 3unit and 2unit. Wasted so much $$
Preliminary mathematics marathon (1 Viewer)
- Thread starter ohexploitable
- Start date
ohexploitable
hey
You sure? It was just slightly different because implicit differentiation was required, after that it was just product rule.
ohexploitable
hey
No working out, I just drew the triangle and used a calculator to do sine rule
A tree stands at the north bank of a river with straight parallel banks running east to west. The angle of elevation to the top of a tree is 28° when measured from point A on the south bank and distant 3 metres to the west of the tree. From another point B on the south bank and distant 5 metres to the east of the tree, the angle of elevation of the tree is 19°. From a point half-way between A and B, find the angle of elevation of the top of the tree.
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hscishard
Active Member
Well..4unit is 4unit. Lol
hscishard
Active Member
No working out, I just visualised the triangle in my head and used a calculator to do sine rule
A tree stands at the north bank of a river with straight parallel banks running east to west. The angle of elevation to the top of a tree is 28° when measured from point A on the south bank and distant 3 metres to the west of the tree. From another point B on the south bank and distant 5 metres to the east of the tree, the angle of elevation of the tree is 19°. From a point half-way between A and B, find the angle of elevation of the top of the tree.
Don't get the question. Is this 3d Trig?
ohexploitable
hey
Here's a diagram:
The question asks you to find the angle of elevation of the tree from the midpoint of AB.
The question asks you to find the angle of elevation of the tree from the midpoint of AB.
ohexploitable
hey
Were are all the 2011ers?
hscishard
Active Member
Is that 3d or 2d?
I still can't see how it works.
I still can't see how it works.
ohexploitable
hey
It's in 3D, the two horizontal lines are the parallel river banks, the line going upwards is the tree.
I can see how it works, but we've just started Trig so I don't think I can do it :\
hscishard
Active Member
What chap. is 3D trig in the Cambridge book?
ohexploitable
hey
I don't think there is 3D trig in Cambridge.
hscishard
Active Member
OMG.
Can you tell me how to do it please?
Can you tell me how to do it please?
hscishard
Active Member
No wait there is in Chp2 in the Year 12 3unit one.
ohexploitable
hey
lol I never actually did the question, seems trippy.
ohexploitable
hey
Oh wait, read the question wrong, it says find the angle of elevation of the tree from the south bank due south of the tree between A and B.
hscishard
Active Member
ohexploitable
hey
Yay! Solved it
hscishard
Active Member
Wha? Whered the 90 come from?Yay! Solved it
Wtf..how is that the mindpoint.
I like the minus part
ohexploitable
hey
Haha yeah the minus, I was like how the fuck can they relate? And then I realised w was common.