Ответ на фото//////////://////////
1)sin(3x-x)=0
2x=πn
x=πn/2
2)2sin2xcos10x=0
sin2x=0⇒2x=πn⇒x=πn/2
cos10x=0⇒10x=π/2+πn⇒x=π/20+πn/10
3)Разделим на cos²x≠0
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
a2=(5+3)/8=1⇒tgx=1⇒x=π/4+πn
1. (√63-√28)*√7=(3√7-2√7)*√7
=√7*√7=7
2. √25a+√36a-√49a
=5a+6a-7a=4a
√54756 = 234
234 234 234 будет 234
( 1 + 3x) / x² = 10
10x² = 1 + 3x
10x² - 3x - 1 = 0
D = b² - 4ac = 9 - 4 × 10 × (-1) = 9 + 40 = 49 = 7²
x1 = ( 3 + 7) / 20 = 0,5
x2 = ( 3 - 7) / 20 = - 4/20 = - 0,2