<em><u>1.</u></em>
<em>одз:</em>
<em>-cosx≥0</em>
<em>cosx≤0</em>
<em>x=-3π/2+2πk</em>
<em>x=-π/2+2πk</em>
<em>x=[-3π/2+2πk;-π/2+2πk] . k=z</em>
<em><em><u>2.</u></em></em>
1)
2sinx-1=0
sinx=1/2
x=π/6+2πk . k=z-не подх под одз
x=5π/6+2πk . k=z
2)
<em>√-cosx+1=0</em>
<em>√-cosx=-1 корней нет</em>
<em>Ответ:x=5π/6+2πk . k=z </em>
Lg 1/5 + log100 25 = log 10 (1/5) + log10² (5)²= <span>lоg10 1/5 + log10 5 =
= </span>log10 (0,2* 5)=log10 <span> 1= 0</span>
а) <span>-2/9+5/18=0,005 и <span>3,9-4,7=-0,8 б) <span>-22/7*1=-3,14 и <span>3/11 =0,27 и <span>-5,6*(-1,2)= 6,72 в)<span> -7,5:(-0,25)=30 и <span>-0,8:(-0,6)=1,33</span></span></span></span></span></span></span>