如图,在ΔABC中,∠B=30°,AC=2,cosC=35.则AB边的长为 .
下列各数:,,,,,,,0.010020003……(每两个非零数字之间多一个0)中,其中无理数有 个.
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(-1)2n =______;(-1)2n+1 =________;
(-0.1)3=_______;
(-5) 2 =________;