oblicz karko: 8sin²80^o−2√3sin40^o−2cos40^o=

Mila: 8sin²(80)−2√3sin(40)−2cos(40)=

	√3		1
=4*[2sin2(80)−(		sin(40)+		cos(40))]=
	2		2

=4*[2sin²(80)−(sin(40)*cos(30)+sin(30)*cos(40))]= =4*[2sin²(80)−sin(30+40)]==4*[2sin²(80)−sin(70)]= =4*[2sin²(80)−cos20]=4*[2cos²(10)−cos20]=

	cos(20)+1
=4*[2*		−cos20]=
	2

=4*[cos(20)+1−cos(20)]=4

Niki: 5+3