求三道高二数学难题及答案!!(不要几何题)
若a平方+b平方=1，求a平方+b平方+ab的取值范围.答案是大于或等于2分之1且小于或等于3绛旓細25.瑙ｏ細锛圛锛夌敱棰樻剰鐭ワ細a1=0.1*0.1*100=1 a2=0.3*0.1*100=3 鈭垫暟鍒 an鏄瓑姣旀暟鍒楋紝鈭村叕姣 q=a2/a1=3 鈭 .an=a1*q^(n-1)=1*3^(n-1)=3^(n-1)(II) 鈭礱2=3 a3=qa2=3*3 =9,a4=9*3=27 鈭碽1+b2+b3+b4+b5+b6=100-(a1+a2+a3)=100-1-3-9=87 鈭垫暟鍒 bn...
绛旓細1.鎹㈠厓娉曪紝璁総=x^2,鍐嶉厤鏂瑰嵆鍙 2.鐪嬪浘锛寈=a,b鏃讹紝f'(x)=0,鍗砯(x)鍥惧儚鍒囩嚎鏂滅巼涓0锛屽彧鏈夌4涓弧瓒 3.璁炬洸绾夸笂涓鐐(a,e^a)鍒扮洿绾胯窛绂绘渶鐭紝璺濈涓篸=|a-e^a-3|/鈭2 娉細鈭氫唬琛ㄦ牴鍙凤紝鍐呯殑鍗充负鏍瑰彿涓嬬殑鏁 褰揹鏈灏忔椂锛屽嵆|a-e^a-3|鏈灏忥紝璁緎=x-e^x-3,鍒檚'=1-e^x锛...
绛旓細涓夈佸畾涔夋硶 鑻ュ姩鐐硅建杩规弧瓒冲凡鐭ユ洸绾跨殑瀹氫箟锛屽彲鍏堣瀹氭柟绋嬶紝鍐嶇‘瀹氬叾涓殑鍩烘湰閲忥紝姹傚嚭鍔ㄧ偣鐨勮建杩规柟绋嬨備緥涓夈侊紙2005骞村箍宸炰簩妯★級鍔ㄥ渾M杩囧畾鐐筆锛堬紞4锛0锛夛紝涓斾笌鍦咰锛歺2+y2锛8x=0鐩稿垏锛屾眰鍔ㄥ渾鍦嗗績M鐨勮建杩规柟绋嬨傚垎鏋愶細鏍规嵁棰樻剰||MC|锛峾MP||=4锛岃鏄庣偣M鍒板畾鐐笴銆丳鐨勮窛绂讳箣宸殑缁濆鍊间负瀹氬硷紝...
绛旓細涓銆併愶紙x-6锛塣2+(y+3)^2=52 鎴栵紙x-14锛塣2+(y+7)^2=202銆戣В锛氫粠鈥滃绉扮偣浠嶅湪杩欏渾涓娾濈湅鍑篨+2Y=0缁忚繃鍦嗗績锛堝渾蹇冨氨鍙互璁句负锛-2b锛宐锛夛級鎵浠ュ彲璁惧渾鐨勬柟绋嬩负锛坸+2b锛塣2+(y-b)^2=r^2 杩欓噷鏄庢樉鐨勬湁涓や釜鏈煡鏁帮細b鍜宺 涓嬮潰鎵句袱涓柟绋嬶細1銆丄鐐瑰彲浠ュ甫鍏ュ緱鍒颁竴涓柟绋嬶紙2+2b锛...
绛旓細鑻骞虫柟+b骞虫柟=1锛屾眰a骞虫柟+b骞虫柟+ab鐨勫彇鍊艰寖鍥.绛旀鏄ぇ浜庢垨绛変簬2鍒嗕箣1涓斿皬浜庢垨绛変簬3
绛旓細2浠=x-2 鍒檟=t+2 鍑芥暟灏变负t+3/t=1+3/t (t>0) 閬楁喚鐨勫憡璇変綘 鏈澶у间负姝ｆ棤绌枫傘傘3 鎶妜闄ゅ埌鍒嗘瘝涓 鍒嗘瘝灏辨槸x+(2/x)杩愮敤鍩烘湰涓嶇瓑寮 鍒嗘瘝鏈灏忓间负2鏍瑰彿2 鍒嗘暟鏈澶у间负鏍瑰彿2
绛旓細4.a1=2锛宎5=162 鏋勬垚绛夋瘮鏁板垪锛宎5=a1*q^4 q^4=a5/a1=81=3^4 鍒檘=卤3a2=a1*q=卤6, a3=a2*q=18, a4=a3*q=卤54杩欎笁涓暟鍒嗗埆鏄6,18,54鎴-6,18,-54 5.搴旇鏄繖3涓暟鐨勫拰涓14锛岀Н涓64锛屽彲璁句笁涓暟鍒嗗埆涓篴1,a2,a3鏋勬垚绛夋瘮鏁板垪锛屽垯鏈 a1*a3=a2² 鍒檃1*a2*...
绛旓細(2)妞渾鐨勭蹇冪巼e=鈭3/2銆傚欢闀緼B浜ゅ彸鍑嗙粨浜庣偣P锛屼綔AA1鍨傚彸鍑嗙嚎鍨傝冻涓篈1锛孊B1鍨傜洿鍙冲噯绾垮瀭瓒充负B1銆傦副F2A锔=e*锔盇A1锔憋紝锔盕2B锔=e*锔盉B1锔便傛墍浠ワ副BB1锔=3锔盇A1锔 涓夎褰AA1鐩镐技涓夎褰BB1锛屽垯锔盤B锔=3锔盤A锔便傦副PF2锔=锔盤A锔+锔盕2A锔=锔盤B锔/3+锔盕2B锔/3=锔盤B锔/3+(锔...
绛旓細abd,bcd,acd鐨勬鐜囩浉鍔 40鍒嗙殑姒傜巼涓1/48锛堢粡妫楠岋紝姒傜巼鍚堜负1锛屾墍浠ユ槸瀵规淮~~锛3锛鏁板鏈熸湜涓20*1/8+25*17/48+30*17/48+35*7/48+40*1/48=鍏蜂綋鐨勬暡璁＄畻鍣ㄢ︹3. B=a2A.浠庢柟宸殑姹傛硶涓婂幓鎯筹紝鍏紡閲岄潰鏈変釜骞虫柟鐨
绛旓細1. b-a=(1+t, 2t-1, t-1)|b-a|^2=(t+1)^2+(2t-1)^2+(t-1)^2 =6t^2-4t+3=6(x-1/3)^2+7/3 鏁呭綋t=1/3鏃讹紝|b-a|鐨勬渶灏忓兼槸鈭21/3 2. B(3,12,0), OB=(3,12,0)|OB|^2=9+144=153 3. BC鐨勪腑鐐瑰潗鏍囨槸D(2,1,4)涓嚎|AD|=3(鐢ㄤ袱鐐归棿璺濈鍏紡锛...
