化簡sin10+cos80+√3sin10cos80.

化簡sin10+cos80+√3sin10cos80.

sin10+cos80+√3sin10cos80
=sin10- sin10-√3sin10sin10
=-√3sin10sin10
=-√3（sin10）^2
=-√3（1-cos20）/2

求英文寫的第一次上網經歷50-80個字檔次低一點就行

Yesterday，my father bought me a computer as my birthdaypresent.ThenI was able to surf on thenet.That's my first time surfing on thenet.Itwas a very interesting and exciting experience.I met a lot of people and read a lot of news.I can even buy things on thenet.Itis veryconvenient.Computerand internet are very good tools in the modern days.

脫式計算共80道

8×25×1.25×16 4.04×250 45.55－（6.82＋15.55）
3.2×99＋3.2 4.8×39＋61×4.8 34.52－17.87－12.23
2.5×56+4.5×65 489×101－489 4.57+3.17+3.43+5.83
（85＋40）×（20－5）578－405÷45×16 4.6×56＋48×4.6－4.6×4
1.3/7×49/9 - 4/3
2.8/9×15/36 + 1/27
3.12×5/6–2/9×3
4.8×5/4 + 1/4
5.6÷3/8–3/8÷6
6.4/7×5/9 + 3/7×5/9
7.5/2 -（3/2 + 4/5）
8.7/8 +（1/8 + 1/9）
9.9×5/6 + 5/6
10.3/4×8/9 - 1/3
11.7×5/49 + 3/14
12.6×（1/2 + 2/3）
13.8×4/5 + 8×11/5
14.31×5/6–5/6
15.9/7 -（2/7–10/21）
16.5/9×18–14×2/7
17.4/5×25/16 + 2/3×3/4
18.14×8/7–5/6×12/15
19.17/32–3/4×9/24
20.3×2/9 + 1/3
21.5/7×3/25 + 3/7
22.3/14××2/3 + 1/6
23.1/5×2/3 + 5/6
24.9/22 + 1/11÷1/2
25.5/3×11/5 + 4/3 26.45×2/3 + 1/3×15
27.7/19 + 12/19×5/6
28.1/4 + 3/4÷2/3
29.8/7×21/16 + 1/2
30.101×1/5–1/5×21
有點暈，忘了脫式計算是什麼樣的，好像有的不符合要求，但我只能找到這些了，希望可以幫到你.