Question

$2cos^2a/2-cosa-1$

нужно упростить

ответ:0

Answer 1

-3*(2*x-0.8) = 2*(x+3.6) - 6*x+2.4-2*x-7.2 , 2*(x+3.6) - 6*x+2.4-2*x-7.2 = 0 - 8*x-4.8 , 0 - 8*x-4.8 = 0*x , 0*x = - 4.8/8*x , - 4.8/8*x = - 0.6

[∅]

 

 

Answer 2

по теории: 

$cos^2(a/2)=(cosa +1)/2$

теперь

$2*(cosa+1)/2-cosa-1$=

=cosa+1-cosa-1=0