设全集U={1,2,3, 4,5, 6,7,8},集合S="{1," 3, 5}, T="{3," 6},则Cu(SUT)="( " )
设是等差数列,若,则数列前8项的和为 ( )
已知集合若,则的取值范围是()
在△ABC中,=10,B=60°,C=45°,则c等于 ()
ΔABC中, ="1," b=, ∠A=30°,则∠B等于 ()
若f(x)=ln(x2-2ax+1+a)在区间上递减,则实数的取值范围为 ()