14tan245°+1sin230°-3cos230°+tan45°cos0°-sin40°cos50°．

题型：不详难度：来源：

1

4

tan245°+

1

sin230°

-3cos230°+

tan45°

cos0°

-

sin40°

cos50°

．

答案

原式=

1

4

×1²+

1

( 1 2 )2

-3×（

3

2

）²+1-

sin40°

sin40°

=

1

4

+4-

9

4

+1-1
=2．