谁能帮我解一下这道题,过程写一下呗谢谢 有哪位数学高手能帮我解一下这道题?请写出过程.谢谢!
\u8c01\u80fd\u5e2e\u6211\u89e3\u4e00\u4e0b\u8fd9\u9053\u9898\uff1f\u9700\u8981\u8fc7\u7a0b\uff0c\u7b54\u6848\u8981\u6b63\u786e\uff0c\u8c22\u8c22\uff013ababa\uff08\u5982\u6b64\u5199,a\u4e0d\u7b49\u4e8eb\uff096=2*3 a\u5fc5\u987b\u662f\u5076\u65700,2,4,6,8a=03+2b\u662f3\u7684\u500d\u6570,3\u662f3\u7684\u500d\u6570
\u6240\u4ee52b\u662f3\u7684\u500d\u6570,\u5373b\u662f3\u7684\u500d\u6570b=3,6,9a=23+2b+9\u662f3\u7684\u500d\u6570,12\u662f3\u7684\u500d\u6570
\u6240\u4ee52b\u662f3\u7684\u500d\u6570,\u5373b\u662f3\u7684\u500d\u6570b=0,3,6,9\u540c\u7406a=4,a=8\u65f6b=0,3...
\u5171\u8ba118\u4e2a
\u9898\u76ee\u6253\u9519\u4e86\u5427\uff0c\u5e94\u8be5\u662f1/sin2x+1/sin4x+1/sin8x+...+1/sin2^nx=cotx-cot2^nx
\u8bc1\u660e\uff1a\u6709\u4e07\u80fd\u516c\u5f0f\uff1asin2x=2tanx/[1+(tanx)^2]
(1)
tan2x=2tanx/[1-(tanx)^2](2),\u5f97
1/sin2^nx={1+[tan2^(n-1)x]^2}/2tan2^(n-1)x
\uff08\u6ce8\uff1a\u7531(1)\u5f0f\u800c\u6765\uff09
=(2-{1-[tan2^(n-1)x]^2})/2tan2^(n-1)x
=2/2tan2^(n-1)x
-
2/tan2^nx
\uff08\u6ce8\uff1a\u7531(2)\u5f0f\u800c\u6765\uff09
=cot2^(n-1)x-cot2^nx
\u6240\u4ee5\u5de6\u8fb9=cotx-cot2x+cot2x-cot4x+cot4x-cot8x+...+cot2^(n-1)x-cot2^nx
=cotx-cot2^nx
\u8bc1\u6bd5\u3002
\u8fd8\u6709\uff0c\u5f52\u7eb3\u6cd5\u662f\u61d2\u4eba\u7684\u505a\u6cd5\uff0c\u4e0d\u5229\u4e8e\u62d3\u5c55\u601d\u7ef4\u3002
所以原不等式等价于不等式|2x+1|≦2/3,
|2x+1|≦2/3等价于-2/3≦2x+1≦2/3
所以-5/3≦2x≦-1/3
所以-5/6≦x≦-1/6
即原不等式的解是-5/6≦x≦-1/6
绛旓細鎵浠-5/3鈮2x鈮-1/3 鎵浠-5/6鈮鈮-1/6 鍗冲師涓嶇瓑寮忕殑瑙f槸-5/6鈮鈮-1/6
绛旓細1.鈶燨M=QM/鈭3=x/鈭3 ON²=3-x²,ON=鈭(3-x²)MN=ON-OM=鈭(3-x²)-x/鈭3 y=x[鈭(3-x²)-x/鈭3]鈶 PN=sin胃*鈭3,OQ=PN/(鈭3/2)=2PN/鈭3=2sin胃 PQ²=3+4sin²胃-2鈭3*2sin胃cos(60掳-胃)PQ²=3+2-2cos2胃-2...
绛旓細瑙d箣寰楋細锝沰=0.5 锝沚=2 鈭磞涓巟涔嬮棿鐨勫嚱鏁板叧绯诲紡锛歽=0.5x+2 (2) 褰搙=0鏃 y=2 鈭村脊绨ф湰韬殑闀垮害涓2cm (3) 褰搚=6鏃 x=8 鈭磋嫢鎸傞噸涓6鍗冨厠鏃讹紝寮圭哀鐨勯暱搴︽槸8cm O(鈭鈭)O~
绛旓細鎵浠ュ彧鑳芥槸95 x 5 鎵浠ヨ繖涓暟鏄199975
绛旓細瑙:璇锋妸鍏蜂綋棰樼洰鍙戣繃鏉ワ紝鏈濂芥槸鍥剧墖锛屾垜绠楃畻 渚嬪:涓嬪浘 姹傝В甯稿井鍒嗘柟绋 璇峰弬鑰 鍚湁鏈煡閲忕殑绛夊紡灏辨槸鏂圭▼浜嗭紝鏁板鏈鍏堝彂灞曚簬璁℃暟锛岃屽叧浜庢暟鍜屾湭鐭ユ暟涔嬮棿閫氳繃鍔犮佸噺銆佷箻銆侀櫎鍜屽箓绛夎繍绠楃粍鍚堬紝褰㈡垚浠f暟鏂圭▼锛氫竴鍏冧竴娆℃柟绋嬶紝涓鍏冧簩娆℃柟绋嬨佷簩鍏冧竴娆℃柟绋嬬瓑绛夈傜劧鑰岋紝闅忕潃鍑芥暟姒傚康鐨勫嚭鐜帮紝浠ュ強鍩轰簬鍑芥暟鐨勫井鍒...
绛旓細瀵逛簬绉垎鍖哄煙锛屾垜浠彲浠ュ厛纭畾鐩寸嚎y=j涓巟涓婃柟鍦嗘垚鐨勬棤鐣屽尯鍩熴傝繖鍙互閫氳繃浠ヤ笅姝ラ瀹屾垚锛氬湪鐩磋鍧愭爣绯讳腑锛屾壘鍑轰笌y=j骞宠鐨勭洿绾匡紱鍦ㄨ鐩寸嚎涓婃壘鍑轰笌x杞寸浉浜ょ殑鐐癸紝杩欎簺鐐瑰氨鏄棤鐣屽尯鍩熺殑杈圭晫锛涘皢杩欎簺鐐硅繛鎺ヨ捣鏉ワ紝灏卞緱鍒颁簡鏃犵晫鍖哄煙鐨勮竟鐣岋紱灏嗘棤鐣屽尯鍩熺殑杈圭晫涓巠=j鐩镐氦鐨勭偣鐨勫潗鏍囷紝灏辨槸鏃犵晫鍖哄煙鐨勯《鐐瑰潗鏍囷紱鏍...
绛旓細3ababa锛堝姝ゅ啓,a涓嶇瓑浜巄锛6=2*3 a蹇呴』鏄伓鏁0,2,4,6,8a=03+2b鏄3鐨勫嶆暟,3鏄3鐨勫嶆暟 鎵浠2b鏄3鐨勫嶆暟,鍗砨鏄3鐨勫嶆暟b=3,6,9a=23+2b+9鏄3鐨勫嶆暟,12鏄3鐨勫嶆暟 鎵浠2b鏄3鐨勫嶆暟,鍗砨鏄3鐨勫嶆暟b=0,3,6,9鍚岀悊a=4,a=8鏃禸=0,3...鍏辫18涓 ...
绛旓細浠 u=x/y, 鍗 x=yu, dx=udy+ydu.浠e叆鏂圭▼锛寀dy+ydu+2(u^3-u)dy=(2u^3-u)dy+ydu=0 鍒嗙鍙橀噺锛宒y/y = du/[u*(1-2u^2)]= [(1/u)+ 2u/(1-2u^2)]du 涓よ竟绉垎锛岃В寰 y=(C*u/(1-2u^2)=(Cxy)/(y^2-2x^2)锛堝叾涓瑿涓哄緟瀹氬父鏁帮級褰搙=1鏃,y=1,浠e叆瑙e緱 C=-1....
绛旓細鍙璇佹槑宸﹁竟涔樹互鍙宠竟鐨勫垎姣=1灏卞彲浠ヤ簡 loga(e)*lna=(lne/lna ) *lna=lne=1 [鐢ㄥ埌鐨勭煡璇嗙偣,鎹㈠簳鍏紡: loga(b)=lnb/lna, 杩樻湁lne=1]
绛旓細鐢辨椂闂村叆鎵嬶紝璁惧皬鏄庨熷害a锛岀埜鐖搁熷害b 鎬昏矾绋媠 鍒檚/a-7s/10a-3s/10b=6 ...鈶 7s/10b=2s/10a ...鈶 鑱旂珛鈶犫憽 鍙緱灏忔槑姝ヨ鐢28鍒嗛挓