without calculator solving e.g. cos (1/2)

[tha boss]

quick method

[TrueTears]

cos(1/2) = cos(1/2)

[onur369]

Do you mean basic angles if so pi/6 ?

[tha boss]

Do you mean basic angles if so pi/6 ?

yea like that how do  you do it by hand

[Truck]

Do you mean basic angles if so pi/6 ?

yea like that how do  you do it by hand

You remember it.

[tha boss]

Do you mean basic angles if so pi/6 ?

yea like that how do  you do it by hand

You remember it.

i cant its too much man

[Hutchoo]

Well, if you remember the sine values, you can remember the cosine values (they're the opposite of each other).

[Truck]

Do you mean basic angles if so pi/6 ?

yea like that how do  you do it by hand

You remember it.

i cant its too much man

Sorrys dude, stare at it for a while, write it out, get someone to repeatedly ask you values (shoot them at you) and you should get it after a while. Gotta love rote memorization!

[xZero]

just fyi. cos(1/2) is just cos(1/2)

if you want to remember the table, just memorise sine(theta), cos(theta) is just the reverse of that and tan(theta) is just sin(theta)/cos(theta)

[thushan]

Try this:

                  0                30                   45                    60                  90
sin        root(0)/2     root(1)/2       root(2)/2          root(3)/2         root(4)/2

cos      root(4)/2     root(3)/2        root(2)/2          root(1)/2         root(0)/2


Note: root(0)/2 = 0, root(1)/2 = 1, root(4)/2 = 2/2 = 1.

To get tan, use sin/cos.

[BlueSky_3]

Or just derive them each time by drawing up a right-angled triangle, 2 since one for pi/3 and pi/6 and another for pi/4.
Over time you should be able to do them in your head. 

[luffy]

Try this:

                  0                30                   45                    60                  90
sin        root(0)/2     root(1)/2       root(2)/2          root(3)/2         root(4)/2

cos      root(4)/2     root(3)/2        root(2)/2          root(1)/2         root(0)/2


Note: root(0)/2 = 0, root(1)/2 = 1, root(4)/2 = 2/2 = 1.

To get tan, use sin/cos.

root(1)/2 = 1?

[Asx4Life]

Construct your own table before starting an exam. This is how I used to construct a table before remembering trig values.
1. label your table           
                  0          30        45         60           90
sin
cos
2.  Go along the sin row numbering each one from 0-4                 
                 0          30         45         60           90
sin            0           1           2            3           4
cos
3. Label the cos row backwards
                 0          30         45         60           90
sin            0           1           2            3            4
cos           4           3           2            1            0
4.Put a square root on all the values
                 0          30         45         60           90
sin            r0          r1         r2          r3            r4                          r=square root
cos           r4          r3         r2           r1           r0
5.Divide all values by 2
                 0          30         45         60           90
sin            (r0)/2    (r1)/2   (r2)/2     (r3)/2      (r4)/2
cos           (r4)/2   (r3)/2    (r2)/2     (r1)/2      (r0)/2

And you got your table! This takes less than 10 seconds if u do it fast

[Lasercookie]

I found it easier to just memorise the little triangle for 30, 45 and 60. You would probably already know the values for sin, cos and tan 0 and 90 off the top of your head anyway.

[REBORN]

Honestly...you should just know it because you've done that many questions.