<span>Д=25+40=65 </span>
<span>х1=(5+корень65)/2 </span>
<span>х2=(5-корень65)/2</span>
α - угол четвёртой четверти, значит Cosα > 0 :
![Cos\alpha =\sqrt{1-Sin^{2}\alpha}=\sqrt{1-(-\frac{\sqrt{7}}{4})^{2}}=\sqrt{1-\frac{7}{16}}=\sqrt{\frac{9}{16}}=\frac{3}{4}](https://tex.z-dn.net/?f=Cos%5Calpha%20%3D%5Csqrt%7B1-Sin%5E%7B2%7D%5Calpha%7D%3D%5Csqrt%7B1-%28-%5Cfrac%7B%5Csqrt%7B7%7D%7D%7B4%7D%29%5E%7B2%7D%7D%3D%5Csqrt%7B1-%5Cfrac%7B7%7D%7B16%7D%7D%3D%5Csqrt%7B%5Cfrac%7B9%7D%7B16%7D%7D%3D%5Cfrac%7B3%7D%7B4%7D)
<em>1) x-4.5≥0; х≥4.5; х∈[4.5;+∞)</em>
<em>2) 2x-0,74≥0; x≥0.37; ∈[0.37;+∞)</em>
<em>3) 4,3-x≥0; х≤4.3; x∈(-∞;4.3]</em>
<em>4) 28-4x≥0; х≤7; х∈(-∞;7]</em>
<em />
Tgˇ2 x -3=0, tgˇ2 x = 3, /tg x/=V(3).
a)tg x = V(3), x= pí/6+k.pí
b)tg x = -V(3), x=2pí/2+k.pí
2.cosx-1=0, 2cosx=1, cosx=1/2
a)x=pí/3+2k.pí
b)x=5pí/3+2k.pí
k=0,1,-1,2,-2,.....
M ≈ -0.8
1) √6-m = √6+0.8= √6.8 ≈ 2.607, т.е. точка С
2) m^2 = (-0.8)^2= 0.64, т.е. точка B
3) m-1 = -0.8-1≈-1.8, т.е. точка А
4) -3/m - оставшаяся точка D