问题
解答题
求下列各式的值:
(1)1+sin245°+cos245°.
(2)2sin30°-2cos60°+sin45°-cos45°
答案
(1)原式=1+(
)2+(2 2
)2=1+2 2
+1 2
=2;1 2
(2)原式=2×
-2×1 2
+1 2
-2 2
=0.2 2
求下列各式的值:
(1)1+sin245°+cos245°.
(2)2sin30°-2cos60°+sin45°-cos45°
(1)原式=1+(
)2+(2 2
)2=1+2 2
+1 2
=2;1 2
(2)原式=2×
-2×1 2
+1 2
-2 2
=0.2 2