问题
填空题
cos15°+sin75°的值是______.
答案
cos15°+sin75°=cos(45°-30°)+sin(45°+30°)=cos45°cos30°+sin45°sin30°+sin45°cos30°+cos45°sin30°
=
×2 2
+3 2
×2 2
+1 2
×2 2
+3 2
×2 2
=1 2
.
+6 2 2
故答案为:
.
+6 2 2
cos15°+sin75°的值是______.
cos15°+sin75°=cos(45°-30°)+sin(45°+30°)=cos45°cos30°+sin45°sin30°+sin45°cos30°+cos45°sin30°
=
×2 2
+3 2
×2 2
+1 2
×2 2
+3 2
×2 2
=1 2
.
+6 2 2
故答案为:
.
+6 2 2