<span><span><span>−3</span>,<span><span><span>5<span>x2</span></span>+<span>6x</span></span>−0</span></span>,<span>5=0</span></span>
<span>Коэффициенты уравнения: </span>
<span><span>a=<span>−3</span></span>,5</span><span>, </span><span>b=6</span><span>, </span><span><span>c=<span>−0</span></span>,5</span>
<span>Вычислим дискриминант: </span>
<span><span>D=<span><span>b2</span>−<span><span>4a</span>c</span></span></span>=</span><span><span><span><span>62</span>−<span><span>4·<span>(<span><span>−3</span>,5</span>)</span></span>·<span>(<span><span>−0</span>,5</span>)</span></span></span>=<span>36−7</span></span>=29</span>
<span>(<span>D>0</span>)</span>, следовательно это квадратное уравнение имеет 2 различных вещественных корня:
Вычислим корни:
<span><span>x<span>(<span>1,2</span>)</span></span>=<span><span><span>−b</span>±<span>√D</span></span><span>2a
</span></span></span><span><span><span><span><span><span>x1</span>=<span><span><span>−b</span>+<span>√D</span></span><span>2a</span></span></span>=<span><span><span><span>−6</span>+5</span>,385</span><span>2·<span>(<span><span>−3</span>,5</span>)</span></span></span></span>=<span><span><span>−0</span>,615</span><span>−7</span></span></span>=0</span>,088
</span><span><span><span><span><span><span>x2</span>=<span><span><span>−b</span>−<span>√D</span></span><span>2a</span></span></span>=<span><span><span><span>−6</span>−5</span>,385</span><span>2·<span>(<span><span>−3</span>,5</span>)</span></span></span></span>=<span><span><span>−11</span>,385</span><span>−7</span></span></span>=1</span>,626</span>
<span><span><span>−3</span>,<span><span><span>5<span>x2</span></span>+<span>6x</span></span>−0</span></span>,<span><span>5=<span>0.5·<span><span>(<span><span>x−0</span>,088</span>)</span><span>(<span><span>x−1</span>,626</span>)</span></span></span></span>=0
</span></span>Ответ:
<span><span><span>x1</span>=0</span>,088</span>
<span><span><span>x2</span>=1</span>,<span>626</span></span>
вот держи
для удобства перепишем уравнение-
cos5x+cos3x=0
cos5x+cos3x=2*cos((5x+3x)/2)*cos((5x-3x)/2)=2*cos4x*cosx
получается
2cos4xcosx=0 (делим на 2)
cos4xcosx=0
1)cos4x=0 или 2)cox=0
1) cos4x=0
4x=ПИ/2+ПИn n принадлежит Z
x=ПИ/8+ПИ/4n
2) cosx=0
x=ПИ/2+ПИn n принадлежит Z
ВСЕ!))
Так ну вообщем не знаю, ну должно быть правильно
1.8*10+32=50
8-y-4(2-3y)=16+3y
8-y-8+12y=16+3y
11y=16+3y
11y-3y=16
8y=16
y=16:8
y=2
1950 - исправны
50 - не исправны
значит р=50/1950; 1/39
Ответ: р=1/39
