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Trigonometric Results (1 Viewer)

Avenger6

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Hi, guys I was doing some revision today and came across these trigonometric results questions and I must have skipped the lesson becuase I have no idea on what I have to do to solve them. Any help on solving the following is greatly appreciated:

4) Simplify the following:
 

Trebla

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Just expand them or remember ASTC....
a) sin θ
b) - cos α
e) 1/tan θ (or cot θ)
 

lyounamu

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Avenger6 said:
Hi, guys I was doing some revision today and came across these trigonometric results questions and I must have skipped the lesson becuase I have no idea on what I have to do to solve them. Any help on solving the following is greatly appreciated:

4) Simplify the following:
4a) Using the formula,
sin (pi - @) = sin(pi)cos@ - cos(pi)sin@
= sin @ (sin(pi) = 0 and cos(pi) = -1)

4c) Using the formula,
cos(pi + @) = cos(pi)cos@ - sin(pi)sin@
= -cos@

4e) tan(pi/2 -@) = cot @ (using the rule that tan (90 - @) = cot @)
 
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foram

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lyounamu said:
4a) Using the formula,
sin (pi - @) = sin(pi)cos@ - cos(pi)sin@
= sin @ (sin(pi) = 0 and cos(pi) = -1)

4c) Using the formula,
cos(pi + @) = cos(pi)cos@ - sin(pi)sin@
= -cos@

4e) tan(pi/2 -@) = cot @ (using the rule that tan (90 - @) = cot @)
I don't think it's worth using the formular. It takes too long.
 

selablad

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Trebla said:
Just expand them or remember ASTC....
My friend's maths teacher made them remember CAST. And then they got totally confused and kept thinking that the 1st quadrant was C and so forth, until I told them about all stations to central...
 

foram

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selablad said:
My friend's maths teacher made them remember CAST. And then they got totally confused and kept thinking that the 1st quadrant was C and so forth, until I told them about all stations to central...
I don't remember it that way. I just think:
sin = y
cos = x
 

selablad

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foram said:
I don't remember it that way. I just think:
sin = y
cos = x
No idea what that means :D Mind you I hated that topic, and our current topic for our exam in a week is based on it :( And I haven't even started learning it yet, because I've been using my maths lessons as sleep periods :uhhuh:

Better go study now :read:
 

lyounamu

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foram said:
I don't think it's worth using the formular. It takes too long.
Yeah. But when you need to prove something, it is better to use formula, isn't it?

But in this case, we are trying to simplify so it will be much easier to use the common knowledge instead of formula.
 

ronnknee

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I suggest that you work more on these types of questions as these are the fundamental identies of trigonometry, and are essential in harder questions

And lmfao "aMUSEd1977 Sucks The Cock"
 

Forbidden.

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A friend once said "All stations to China", wtf.

ronnknee said:
I suggest that you work more on these types of questions as these are the fundamental identies of trigonometry, and are essential in harder questions

And lmfao "aMUSEd1977 Sucks The Cock"
Fully agree.
 

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