體溫 | 36.2 | 36.3 | 36.5 | 36.6 | 36.8 |
天數(shù)天 | 3 | 3 | 4 | 2 | 2 |
這14天中,小寧體溫的眾數(shù)和中位數(shù)分別為( )
甲 | 乙 | 丙 | 丁 | |
24 | 24 | 23 | 20 | |
2.1 | 1.9 | 2 | 1.9 |
下列3×3網(wǎng)格圖都是由9個(gè)相同的小正方形組成,每個(gè)網(wǎng)格圖中有3個(gè)小正方形已涂上陰影,請(qǐng)?jiān)谟嘞碌?個(gè)空白小正方形中,按下列要求涂上陰影:
(請(qǐng)將三個(gè)小題依次作答在圖1、圖2、圖3中,均只需畫(huà)出符合條件的一種情形)
姓名 | 行為規(guī)范 | 學(xué)習(xí)成績(jī) | 體育成績(jī) | 藝術(shù)獲獎(jiǎng) | 勞動(dòng)衛(wèi)生 |
李銘 | 10 | 10 | 6 | 9 | 7 |
張晶晶 | 10 | 8 | 8 | 9 | 8 |
王浩 | 9 | 7 | 9 | 8 | 9 |
【例1】求代數(shù)式的最小值.
解:.
因?yàn)?img class="mathml" src="http://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E%28%3C%2Fmn%3E%3Cmi%3Ex%3C%2Fmi%3E%3Cmo%3E%2B%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmsup%3E%3Cmrow%3E%3Cmn%3E%29%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsup%3E%3Cmo%3E%E2%89%A5%3C%2Fmo%3E%3Cmn%3E0%3C%2Fmn%3E%3C%2Fmath%3E" style="max-width:100%;vertical-align: middle;"> , 所以 , 即代數(shù)式的最小值為3.
【例2】若 , 求、的值.
解:因?yàn)?img class="mathml" src="http://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsup%3E%3Cmrow%3E%3Cmi%3Em%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsup%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmi%3Em%3C%2Fmi%3E%3Cmi%3En%3C%2Fmi%3E%3Cmo%3E%2B%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmsup%3E%3Cmrow%3E%3Cmi%3En%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsup%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmn%3E8%3C%2Fmn%3E%3Cmi%3En%3C%2Fmi%3E%3Cmo%3E%2B%3C%2Fmo%3E%3Cmn%3E1%3C%2Fmn%3E%3Cmn%3E6%3C%2Fmn%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E0%3C%2Fmn%3E%3C%2Fmath%3E" style="max-width:100%;vertical-align: middle;"> ,
所以 ,
即 ,
因?yàn)?img class="mathml" src="http://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E%28%3C%2Fmn%3E%3Cmi%3Em%3C%2Fmi%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmi%3En%3C%2Fmi%3E%3Cmsup%3E%3Cmrow%3E%3Cmn%3E%29%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsup%3E%3Cmo%3E%E2%89%A5%3C%2Fmo%3E%3Cmn%3E0%3C%2Fmn%3E%3C%2Fmath%3E" style="max-width:100%;vertical-align: middle;"> , ,
所以 ,
即.
若是等腰三角形,且滿(mǎn)足 , 求的周長(zhǎng);
若 , 且 , 求中最大邊上的高.