- 16(0,1p - t)² = - 16(0,01p² - 0,2pt + t²) = - 0,16p² + 3,2pt - 16t²
(0,5x + 1,4y)² = 0,25x² + 1,4xy + 1,96y²
![9z ^{2} -7z +m=9z ^{2} -7z+ \frac{49}{36} =9 z ^{2} -7z+1 \frac{13}{36}= (3z- \frac{7}{6} ) ^{2} =](https://tex.z-dn.net/?f=9z+%5E%7B2%7D+-7z+%2Bm%3D9z+%5E%7B2%7D+-7z%2B+%5Cfrac%7B49%7D%7B36%7D+%3D9+z+%5E%7B2%7D+-7z%2B1+%5Cfrac%7B13%7D%7B36%7D%3D+%283z-+%5Cfrac%7B7%7D%7B6%7D+%29+%5E%7B2%7D+%3D)
![(3z-1 \frac{1}{6}) ^{2}](https://tex.z-dn.net/?f=%283z-1+%5Cfrac%7B1%7D%7B6%7D%29+%5E%7B2%7D++)
![m=1 \frac{13}{36}](https://tex.z-dn.net/?f=m%3D1+%5Cfrac%7B13%7D%7B36%7D+)
2x +tq²x *cos²x =2x +sin²x .
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(3x - 6)/(x+6)(x-6) ≤ 0 ;
3(x-2)(x+6)(x-6) ≤ 0 ;
(x-2)(x+6)(x-6) ≤ 0 ;
методом интервалов :
- + - +
---------------- (-6)----------------- [2] -------------- (6)----------------
ответ : x∈ ( -∞ ; 6) U [2 ;6) .
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2sin(π/2 +x)cos(π/2 - x)= sin(π+x) ; x ∈ (90° ; 500°) .
2cosx*sinx = -sinx ;
2sinx(cosx - 1/2) = 0 ;
[ sinx =0 ; cosx =1/2. [ x =π*k; x= -π/3 +2π*k ; x=π/3+2π*k , k∈Z.
x =\\ 180° ;360° \ \ 300° \ \ 420° \\
ответ : 4.
1). 6y(2+y)=12y+6y^2; 2). (d+5)(d-5)= d^2-25.
1. 7-а<7-b
2. -7.3>-8
<u> 7.3>4 </u>
0>-4
3. b>0
a>0
1. Разность арифметической прогрессии:
![d=a_2-a_1=6-2=4](https://tex.z-dn.net/?f=d%3Da_2-a_1%3D6-2%3D4)
. Тогда восьмой член этой прогрессии равен
2. В условии опечатка. Предположу , что a1 = -25. Тогда
![a_{30}=a_1+29d=-25+29\cdot5=120](https://tex.z-dn.net/?f=a_%7B30%7D%3Da_1%2B29d%3D-25%2B29%5Ccdot5%3D120)
3.
![S_{15}= \dfrac{2a_1+14d}{2}\cdot15= 15(a_1+7d)=15(2+7\cdot5)=555](https://tex.z-dn.net/?f=S_%7B15%7D%3D+%5Cdfrac%7B2a_1%2B14d%7D%7B2%7D%5Ccdot15%3D+15%28a_1%2B7d%29%3D15%282%2B7%5Ccdot5%29%3D555)
4.
![d_n=2n+1](https://tex.z-dn.net/?f=d_n%3D2n%2B1)
![d_1=2\cdot1+1=3\\ d_2=2\cdot2+1=5\\ \\ d^*=d_2-d_1=5-3=2](https://tex.z-dn.net/?f=d_1%3D2%5Ccdot1%2B1%3D3%5C%5C+d_2%3D2%5Ccdot2%2B1%3D5%5C%5C+%5C%5C+d%5E%2A%3Dd_2-d_1%3D5-3%3D2)
5.
![S_{21}= \frac{2a_1+20d}{2}\cdot21=21(a_1+10d)=21(3+10\cdot2.5)= 588](https://tex.z-dn.net/?f=S_%7B21%7D%3D+%5Cfrac%7B2a_1%2B20d%7D%7B2%7D%5Ccdot21%3D21%28a_1%2B10d%29%3D21%283%2B10%5Ccdot2.5%29%3D+588)