新PP Math考題

[Cher]

快要正式考試了
今天做了新pp
有種想哭卻哭不出來的沮喪...

有兩題想請教各位大大...
(新pp好像沒有很多人在討論
我可以一次問兩題嗎???)

(1) In the rectangular coordinate system show above,(對不起...我不會抓圖耶...就是一個直角坐標圖...), does the link K (not shown) intersect quandrant II?
(1) The slope of K is -1/6
(2) The y-intercept of K is -6

Ans: A

這題我做的時候是憑感覺猜的,可是怕怕的
可以請哪位大大教我一下該怎麼思考好嗎???


(2) A circular jogging track forms the edge of a circular lake that has a diameter of 2 miles. Johnna walked once around the track at the average rate of 3 miles per hour. If t represents the number of hours it took Johnna to walk completely around the lake, which of the following is a correct statement?

(A) 0.5< t < 0.75
(B) 1.75< t < 2.0
(C) 2.0< t < 2.5
(D) 2.5< t < 3.0
(E) 3.0< t < 3.5

Ans: C

這題我做了兩次答案都是1.多..
根本沒有選項...怎麼會這樣呢...
是我哪裡想錯了嗎
想請各位大大幫幫我

謝謝!!!

[micki]

(2) A circular jogging track forms the edge of a circular lake that has a diameter of 2 miles. Johnna walked once around the track at the average rate of 3 miles per hour. If t represents the number of hours it took Johnna to walk completely around the lake, which of the following is a correct statement?

(A) 0.5< t < 0.75
(B) 1.75< t < 2.0
(C) 2.0< t < 2.5
(D) 2.5< t < 3.0
(E) 3.0< t < 3.5

Ans: C

湖的直徑是2 =>半徑是 1
慢砲道是湖的外圍 跑道長就以圓周長代替

(2 * 3.14 * 1 )/ 3 = 2.09
所以答案是 C

[Cher]

(2) A circular jogging track forms the edge of a circular lake that has a diameter of 2 miles. Johnna walked once around the track at the average rate of 3 miles per hour. If t represents the number of hours it took Johnna to walk completely around the lake, which of the following is a correct statement?

(A) 0.5< t < 0.75
(B) 1.75< t < 2.0
(C) 2.0< t < 2.5
(D) 2.5< t < 3.0
(E) 3.0< t < 3.5

Ans: C

湖的直徑是2 =>半徑是 1
慢砲道是湖的外圍 跑道長就以圓周長代替

(2 * 3.14 * 1 )/ 3 = 2.09
所以答案是 C

啊...
我算成用圓面積下去算了啦
難怪怎麼算都是1.多...
謝謝micki大大
謝謝!!!

[汪汪北鼻]

請將此篇題號標好，不然就無法歸類

[pimi]

(1) In the rectangular coordinate system show above, does the link K (not shown) intersect quandrant II?
(1) The slope of K is -1/6
(2) The y-intercept of K is -6

Ans: A

附上圖片, 請問這堤如何解出A阿？？
我是選B, 因為與y的交點是-6, 應該怎麼畫line K, 都會經過第二項線吧

[wind31526]

(1) In the rectangular coordinate system show above, does the link K (not shown) intersect quandrant II?
(1) The slope of K is -1/6
(2) The y-intercept of K is -6


A選項 負斜率所以一定會經過第二象限
B選項 如果K是"平行X軸的線"或者未過第二象限的"正斜率"都不會過第二象限

所以答案是A~

[wind31526]

(1) In the rectangular coordinate system show above, does the link K (not shown) intersect quandrant II?
(1) The slope of K is -1/6
(2) The y-intercept of K is -6


A選項 負斜率所以一定會經過第二象限
B選項 如果K是"平行X軸的線"或者未過第二象限的"正斜率"都不會過第二象限

所以答案是A~

[pimi]

感激！！

不過還是有小問題要請教大大
負斜率也有可能是只通過Ｉ, ＩＩＩ, ＩＶ象限的直線
為何負斜率一定會經過第二象限　@ @

[wind31526]

感激！！

不過還是有小問題要請教大大
負斜率也有可能是只通過Ｉ, ＩＩＩ, ＩＶ象限的直線
為何負斜率一定會經過第二象限　@ @

你把那條線繼續延伸下去一定會和第二象限有交叉到阿~

[pimi]

不好意思, 我耍了白痴～