Y`=[(1-cos4x)`*sin4x-(sin4x)`(1-cos4x)]/sin²4x=
=(4sin4x*sin4x-4cos4x+4cos²4x)/sin²4x=[4(sin²4x+cos²4x)-4cos4x]/sin²4x=
=(4-4cos4x)/sin²4x=4(1-cos4x)/sin²4x=2sin²2x/(4sin²2xcos²2x)=
=1/(2cos²2x)
X=11-12y
5(11-12y)-3y+8=0
55-60y-3y+8=0
-63y+63=0
-63y=-63
y=1
x=11-12*1=11-12= -1
Ответ: (-1; 1)
3 ³/₄ : (2 ⁴/₇ - 1 ¹/₁₂)=
=¹⁵/₄ : (¹⁸/₇ - ¹³/₁₂)=
=¹⁵/4 : (<u>18*12 - 13*7</u>) =
7*12
=<u>15 </u>* <u> 84 </u> =
4 125
= <u>3 </u>* <u>21 </u>=
1 25
=<u> 63 </u>= 2 ¹³/₂₅
25
Ответ:
А - 4, Б - 3, В - 1