help please

[deft moat]

Cos15° how do I calculate this

[past pike]

We know:

$\ 2\pi = 360$°

$\ \Rightarrow \frac{\pi}{180} = 1$°

$\ \Rightarrow \frac{\pi}{180}\cdot 15 = \frac{\pi}{12} = 15$°

[coarse basalt]

adonhs

[past pike]

Now

$\cos\bigg(\frac{\pi}{12}\bigg) = cos\bigg(\frac{\pi}{4} - \frac{\pi}{6}\bigg)$

[coarse basalt]

adonhs

[past pike]

Now you can use cosinus addition

Notice:

$\ \frac{\pi}{12} = \frac{\pi}{4} - \frac{\pi}{6}\

\ \Rightarrow 15\text{°} = 45\text{°} - 30\text{°} \$

[coarse basalt]

adonhs
Compile Error! Click the reaction for more information.
(You may edit your message to recompile.)

[past pike]

cosinus addition theorem:

$\ cos(a \pm b) = cos(a)cos(b) \mp sin(a)sin(b)\$

[coarse basalt]

adonhs

[distant wyvern]

bro is quick with the latex

this bot is so useful

[past pike]

yeah otherwise without we would be doomed haha