A) 700/12,5 < 630/10,5
56 < 60
Б) 700/14 > 630/14
50 > 45
<span>sin2a+sin4a=2sin3a*cosa</span>
<span><span>cos2a cosa=1/2 (cosa+cos3a)</span></span>
<span><span>2sin3a*cosa<span>+sin6a=4 sin3a*1/2 (cosa+cos3a)</span></span></span>
<span><span><span>2sin3a*cosa+sin6a=2sin3a cosa+2sin3a*cos3a</span></span></span>
<span><span><span>sin6a=2sin3a*cos3a</span></span></span>