<span> (2 7/20+3 11/16):24,15-0,07*1 3/7=0,15</span>
5sin²x-5sinxcosx+2cos²x-sin²x-cos²x=0
4sin²x-5sinxcosx+cos²x=0/cos²x
4tg²x-5tgx+1=0
tgx=a
4a²-5a+1=0
D=25-16=9
a1=(5-3)/8=1/4⇒tgx=1/4⇒x=arctg1/4+πn,n∈z
a2=(5+3)/8=1⇒tgx=1⇒x=π/4+πn,n∈z
(x-1)⁴ - 2(x-1)² - 3 = 0
(x-1)²=t t≥0
t² - 2t - 3 = 0
D=4+12=16=4²
t₁₂=(2+-4)/2 = -1 3
t₁=-1 НЕТ t≥0
t₂=3
(x-1)²=3
x² - 2x + 1 =3
x² - 2x - 2 = 0
D=4+8=12
x₁₂=(2+-√12)/2 = 1+√3 1-√3
Ответ 1+√3 1-√3