所屬科目:教甄◆數學
1. 在某場比賽中,五位評審各給出一個介於 1 到 10 之間的整數分數,並計算這五位評審所給出分數的算術平均數、中位數和眾數。已知五個分數的算術平均數為 7、中位數為 8 且眾數為 9,請找出所有可能的分數組合。
2. 試求?
3. 平面 E 通過(2,-2,-1)及(4,-4,-3)。若P ( a, b,c ) 在平面 E 上的投影點為 Q(1,4,0),且,求 P 的坐標?
4. 已 知A= ,其中ai∈ N, (i = 1, 2,3, 4,5 ) 。 設a1<a2<a3<a4<a5且 A∩B { a1, a4} ,若 a1+a4=10 ,且 A∪B 元素之和為 224,求集合 A=?
5. 85 藍歡慶營業一周年,凡買飲料超過百元者,皆贈送一張刮刮樂彩劵。右圖為其中一種形式,此彩劵共有 9 格,內有四個 1、三個 2、二個 3,玩法是從中任刮 2 格兌獎,否則作廢。若所刮 2 格的數字相同,則可得到此數字 72 倍之等價折價劵;若所刮 2 格的數字相異,則只能領紀念品一份。今小胖拿到一張刮刮樂彩劵,試問小胖刮得折價劵金額之期望值?
6. 求平面上滿足 x3y2 − x2y2 − xy4 + xy3 ≥ 0 且 0 ≤ x ≤ y 的區域面積?
7. 如圖, 2∠BAC = 3∠ABC ,且 D 在上,使得 ∠DAC = 2∠DAB 。假設 = a, = b ,= e。 請用 a、b 和 c 表示 d 和 e。求(d,e)=?
8. H 為△ABC 的垂心,cos B= 、cos C= 。若 於 E,且於 F。求 =?
9. 設複數Z1 = −1 ++ i,其中a ∈ R且a ≠-,求Arg(Z3) = ?
10. A triangle with interior angles 30° and 45°, and the radius of the circumcircle is 4. What is the area of the triangle?
11. George throws three unbiased dice and removes all of the dice that come up with a 5 or 6. Martha then throws the dice that remain, if any. Determine the probability that exactly one of Martha's dice shows a 5 or 6.
12. In the diagram shown, M is the mid-point of PQ. The line Ps bisects ∠RPQ and intersects RQ at S. The line sT is parallel to PR and intersects PQ at T. The length of PQ is 12 and the length of MT is 1. The angle sQT is 120°. What is the length of sQ?
13. The first two terms of an infinite geometric sequence, in order, are3log3x, 2log3x, where x > 0.The first three terms of an arithmetic sequence, in order, areLet s6 be the sum of the first 6 terms of the arithmetic sequence. Given that s6 is equal to one third of the sum of the infinite geometric sequence, find x.
14. A geometric transformation T:(x, y) → (x′, y′) consists of three transformations in order:● A rotation ofθ radians (0 ≤θ< 2π) about the origin, followed by● An enlargement with scale factor 2, centred at the origin, followed by● A translation of 1 unit right and 3 units down.Given that the transformation T maps the point to itself, find the angle θof the rotation.
1. 已知 n 為任意正整數時,數列⟨an⟩的前 n 項和sn使得是一個定值,試證明:⟨an⟩必不為等比數列。
2. 今空間中位於平面 F 上的一正△ABC 在另一平面 E 上的投影為△A'B'C' ,已知 △A'B'C' 之三邊長分 別為 ,若 θ表平面 E 與平面 F 之夾角,則 cosθ = ?
3. 已知 a,b 為的兩個相異實根,試求 ab。