问题
解答题
(1)sin30°+cos45°;
(2)sin260°+cos260°-tan45°.
答案
由题意(1)sin30°+cos45°=
+1 2
=2 2 1+ 2 2
(2)sin260°+cos260°-tan45°=(
)2+(3 2
)2-1=1 2
+3 4
-1=01 4
(1)sin30°+cos45°;
(2)sin260°+cos260°-tan45°.
由题意(1)sin30°+cos45°=
+1 2
=2 2 1+ 2 2
(2)sin260°+cos260°-tan45°=(
)2+(3 2
)2-1=1 2
+3 4
-1=01 4