1. a = 4; b = 36
1/√4 - √36 = 1/2 - 6 = 0,5 - 6 = -5,5
2. a = 100; b = 324
1/√100 - √324 = 1/10 - 18 = 0,1 - 18 = -17,9
3. a = 16; b = 289
1/√16 - √289 = 1/4 - 17 = 0,25 - 17 = -16,75
4. a = 4; b = 100
1/√4 - √100 = 1/2 - 10 = -,5 - 10 = -9,5
1+tg²x=1/cos²x
1+2=1/cos²x
1/cos²x=3, ⇒cos²x=1/3
7-3*cos²x=7-3*(1/3)=7-1=6
ответ: 6
Решение
<span>8cos^2a -2 - 4cos2a = 8cos^2</span>α - 4*(2cos^2α - 1) - 2 =
= 8cos^2α - 8cos^2α + 4 - 2 = 2
Х=0 у=2
у=0 х= -1 1/3
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15 - 12a -12a+7=22-24a
подставим: 22-24* 0,5=22-12=10