圍建一個(gè)面積為360m2的矩形場地.要求矩形場地的一面利用舊墻.其它三面圍墻要新建.在舊墻的對面的新墻上要留一個(gè)寬度為2m的進(jìn)出口.如圖所示.已知舊墻的維修費(fèi)用為45元/m,新墻的造價(jià)為180元/m,設(shè)利用的舊墻的長度為x m.圍墻的總費(fèi)用為y元 (Ⅰ)將y表示為x的函數(shù): (Ⅱ)試確定x,使修建此矩形場地圍墻的總費(fèi)用最小.并求出最小總費(fèi)用. 查看更多

 

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(本題滿分15分)已知直線與曲線相切

1)求b的值;

2)若方程上恰有兩個(gè)不等的實(shí)數(shù)根,求

①m的取值范圍;

②比較的大小

 

 

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((本題滿分15分)
某有獎(jiǎng)銷售將商品的售價(jià)提高120元后允許顧客有3次抽獎(jiǎng)的機(jī)會(huì),每次抽獎(jiǎng)的方法是在已經(jīng)設(shè)置并打開了程序的電腦上按“Enter”鍵,電腦將隨機(jī)產(chǎn)生一個(gè)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        1~6的整數(shù)數(shù)作為號碼,若該號碼是3的倍數(shù)則顧客獲獎(jiǎng),每次中獎(jiǎng)的獎(jiǎng)金為100元,運(yùn)用所學(xué)的知識說明這樣的活動(dòng)對商家是否有利。

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(本題滿分15分)

已知函數(shù)

(1)求的單調(diào)區(qū)間;

(2)設(shè),若上不單調(diào)且僅在處取得最大值,求的取值范圍.

 

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(本題滿分15分)已知拋物線),焦點(diǎn)為,直線交拋物線兩點(diǎn),是線段的中點(diǎn),

  過軸的垂線交拋物線于點(diǎn),

  (1)若拋物線上有一點(diǎn)到焦點(diǎn)的距離為,求此時(shí)的值;

  (2)是否存在實(shí)數(shù),使是以為直角頂點(diǎn)的直角三角形?若存在,求出的值;若不存在,說明理由。

 

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(本題滿分15分)設(shè)函數(shù)

(Ⅰ)若函數(shù)上單調(diào)遞增,在上單調(diào)遞減,求實(shí)數(shù)的最大值;

(Ⅱ)若對任意的,都成立,求實(shí)數(shù)的取值范圍.

注:為自然對數(shù)的底數(shù).

 

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