Question

计算：
①

tan60°-tan45°

1+tan60°•tan45°

+2sin60°
②

(4sin30°-tan60°)(cot30°+4cos60°)

．

Answer 1

①原式=

3 -1

1+ 3 ×1

=

( 3 -1)2

2

=2-

3

；
②原式=

(4× 1 2 - 3 )( 3 +2)

=

(2- 3 )(2+ 3 )

=1．