sin a + sin b Tomek: jak dojść z sinα+sinβ do 2*sin((α+β)/2)*cos((α−β)/2)

Eta: oznacz : a+b= α i a−b=β to: sin(a+b)= sina *cosb+cosa*sinb i sin (a−b)= sina*cosb−cosb*sina (**) sin(a+b)+ sin(a−b)= 2sina*cosb a+b=α a+b=α a−b=β −a+b = −β −−−−−−−− −−−−−−−−−−

	α+β		α−β
2a= α+β ⇒ a=		2b= α−β ⇒ b=
	2		2

	α+β		α−β
(**) sinα+snβ= 2sin		*cos
	2		2

i bingo