Question

could you help me with one more thing? @satellite73

Answer 1

sure if i know it

Answer 2

you know it.

Answer 3

how can I derivate double Angle Formulas from the sum of Two Angles?

Answer 4

by changing \(2x\) in to \(x+x\) and using it
i.e put
\[\sin(x+y)=\sin(x)\cos(y)+\cos(x)\sin(y)\] and make it
\[\sin(x+x)=...\]

Answer 5

in simple english, where you see a \(y\) replace it by an \(x\)

Answer 6

oh ok so I'm allowed to just do that?

Answer 7

i give you permission,
don't tell

Answer 8

lol yes
you get it essentially in one step

Answer 9

haha alright thanks again :)

Answer 10

yw
since you probably have the double angle formula written down you can check that your answer is correct
you will get 3 different ones for the double angle formula for cosine
that one turns out to be most useful