Ответы и объяснения

2013-06-27T17:41:45+04:00

1) 5^12*6^12/30^9 = (5*6)^12/30^9 = 30^12/30^9 = 30^12-9 = 30^3 = 27000

2) 2V5*4V15*5V3 = 2*4*5V5*15*3 = 40V225 = 40*15 = 600

3) log6(5/36)+log6(1/5) = log6(5/36*1/5) = log6(1/36) = log6(6^-2) = -2

4) cosa/2sina - sina/2cosa = 2cos^2a- 2sin^2a/4sinacosa = 2(cos^2a-sin^2a)/4sinacosa = cos^2a-sin^2a/2sinacosa = cos2a/sin2a = ctg2a

2013-06-27T20:42:37+04:00