exact values (1 Viewer)

[frippyful]

i need i list of exact values from trig. like the unit circle and pi and stuff like that. i have massive trouble remembering any kind of exact value, so could someone help me by providing a list of all basic exact values that exist in hsc mathematics or extension

thanks so much!

 

[IamBread]

Do you know the 2 triangles?

 

[IamBread]

There is the 2 triangles. You can get exact values from them.

 

[Carrotsticks]

I absolutely despise those triangles.

I think it is a poor way of understanding where the exact values come from.

 

[such_such]

I absolutely despise those triangles.

I think it is a poor way of understanding where the exact values come from.

Where do they come from? Unit circle?

 

[Carrotsticks]

Where do they come from? Unit circle?

Exactly (pun intended).

 

[SpiralFlex]

Exactly (pun intended).

A double pun would have occurred if eg155 posted.

eg-xactly!

 

[frippyful]

hey thanks for all your help!
but my teacher said something the other day about cos pi = 1 ? i honestly do not get that i was just like, "wtf is that?" so can someone explain that to me and if there are other exact values involving pi and trig.

 

[Cl324]

for trig exact values just use the calculator!

 

[SpiralFlex]

for trig exact values just use the calculator!

Nope. You need to understand the theory behind it, besides your "BOS approved" calculator will not give you your answer in surds. Only the cheat ones do.

 

[Cl324]

just square it to get the answer in surds

Never used the triangles in mah lyf but there pretty easy to remember anyways
One is an equilateral with side length of 2
The other is isosceles with side length one

 

[SpiralFlex]

just square it to get the answer in surds

Never used the triangles in mah lyf but there pretty easy to remember anyways
One is an equilateral with side length of 2
The other is isosceles with side length one

That's cheating. Best to remember.

 

[Carrotsticks]

just square it to get the answer in surds

Never used the triangles in mah lyf but there pretty easy to remember anyways
One is an equilateral with side length of 2
The other is isosceles with side length one

May I present... a rote learner.

 

[Timske]

hey thanks for all your help!
but my teacher said something the other day about cos pi = 1 ? i honestly do not get that i was just like, "wtf is that?" so can someone explain that to me and if there are other exact values involving pi and trig.

Cospi is actually = -1 pi = 180 degrees if u look at the cos graph at 180 cos is

-1.

 

[Shadowdude]

View attachment 24302

There is the 2 triangles. You can get exact values from them.

^ That, pretty much.

Those angles of pi/4, pi/3 and pi/6 are used regularly - and getting their exact values quickly is a nice little bonus. Rote learning perhaps, but they are used regularly enough - I suppose - that rote learning those triangles are worthwhile.

Note: I said learn the triangles, not the values.

 

[frippyful]

Cospi is actually = -1 pi = 180 degrees if u look at the cos graph at 180 cos is

-1.

sorry, i meant -1, so what are the other values for sine and tan and stuff like that.
this is exactly the stuff i honestly do not remember learning

 

[Timske]

http://www.google.com.au/imgres?q=g...tbnw=125&start=15&ndsp=19&ved=1t:429,r:2,s:15

 

[Sanical]

Here's my way of memorising:

All you need to do is just memorise the first row (sin row)
Then, for cos, it's just the same numbers as the sin row except its backwards. Eg. sin30 = 1/2. Therefore, going backwards, cos60=1/2
Then, for tan, it's just the sin value divided by the cos value going downwards Eg. sin45 = and cos45 = . Therefore tan45 =

So yeah, you just need to memorise 1 line to get the rest. After a while, you'll memorise them all.

 

[Shadowdude]

^ or just learn two triangles

Simple.

 

[Sanical]

it was simply an alternative (which I used).