( a+b/a-2b/a+b)*(a+b)=а+в-2в+а=(2а-в)*(а+в)=2а^+2aв-ав-в^2=2a^2+aв-в^2
<span>3. 5x^2-(5+√3)x+√3=0
</span>x(3.5x-5-√3)=-√3
x1=-√3
3.5x-5-√3+√3=0
3.5x=5
x2=1.43
<span><span>3<span>x2</span> - 124x - 84 = 0</span>
<span><span>D = (-124)2 - 4·3·(-84)</span> = 16384</span>
<span><span><span>x1 = </span><span>124 - √16384</span> = <span><span>-2</span>3</span></span>2·3</span>
<span><span><span>x2 = </span><span>124 + √16384</span> = 42</span><span>2·3
</span></span></span>
Y=√(1-sin²t)/sin t=cos t/sin t=ctg t.