（1）2sin260°-3tan30°-2cos245°+12tan45°；（2）2sin30°4cos60°-1+cos30°tan60°．

Question

（1）2sin²60°-√(3)tan30°-2cos²45°+(1)/(2tan45°)；
（2）(2sin30°)/(4cos60°-1)+(cos30°)/(tan60°)．

Answer 1

（1）原式=2×（(√(3))/(2)）²-√(3)×(√(3))/(3)-2×（(√(2))/(2)）²+(1)/(2)
=2×(3)/(4)-1-2×(1)/(2)+(1)/(2)
=(3)/(2)-1-1+(1)/(2)
=0；

（2）原式=(2×(1)/(2))/(4×(1)/(2)-1)+((√(3))/(2))/(√(3))
=(1)/(2-1)+(1)/(2)
=1+(1)/(2)
=(3)/(2)．