MATLAB第四章符号运算2-微分方程求解.pdf

绗洓绔燤ATLAB 绗﹀彿杩愮畻 褰 鏈 闇 Email: pengzhaoxia@buaa.edu.cn 鍖椾含鑸 绌鸿埅澶╁ぇ瀛 浜ら€氱瀛︿笌宸ョ▼ 瀛﹂櫌 2014 骞 10 鏈?3 鏃 褰湞闇 (鍖椾含鑸┖鑸ぉ澶у) MATLAB鍩虹鍙婂伐绋嬪簲鐢 2014 骞 10 鏈 23 鏃 1 / 1 鏈珷涓昏鍐呭 褰湞闇 (鍖椾含鑸┖鑸ぉ澶у) MATLAB鍩虹鍙婂伐绋嬪簲鐢 2014 骞 10 鏈 23 鏃 2 / 1 绾挎€ф柟绋嬬粍鐨勮В鏋愯В 绾挎€ф柟绋嬬粍鐨勮В鏋愯В 鈾 浠ｆ暟鏂圭▼ 锛堥潪绾挎€э級姹傝В锛歴olve s=solve(f,v) 锛氭眰鏂圭▼鍏充簬鎸囧畾鑷彉閲忕殑瑙 s=solve(f) 锛氭眰鏂圭▼鍏充簬榛樿 鑷彉閲忕殑瑙 f 鍙 浠ユ槸鐢ㄥ瓧绗︿覆锛屾垨绗﹀彿琛ㄨ揪寮 鏉ヨ〃绀虹殑鏂圭▼ 鑻 鏄瓧绗︿覆锛屽彲 浠ヤ笉鍚瓑鍙凤紝琛ㄧず瑙ｆ柟绋媐=0 鑻 鏄鍙疯〃杈惧紡锛屼笉鑳藉惈绛夊彿 褰湞闇 (鍖椾含鑸┖鑸ぉ澶у) MATLAB鍩虹鍙婂伐绋嬪簲鐢 2014 骞 10 鏈 23 鏃 3 / 1 绾挎€ф柟绋嬬粍鐨勮В鏋愯В 浠ｆ暟鏂圭▼鐨勬眰瑙olve 瑙ｆ柟绋媥 3 鈭 3 * x + 1 = 0. f 鏄鍙疯〃杈惧紡 驴驴 syms x ; f=x^3-3*x+1; s=solve (f ,x) 娉ㄦ剰锛氫笉鑳藉啓鎴恠=solve(f=0,x) f 鏄瓧绗︿覆 驴驴 s=solve (鈥檟^3-3*x+1 鈥?鈥檟 鈥? 驴驴 s=solve (鈥檟^3-3*x+1=0 鈥?鈥檟 鈥? 娉ㄦ剰 锛氬彲 浠ヤ笉鍚瓑鍙凤紝琛ㄧず瑙ｆ柟绋媐=0锛屼絾鏄篃鍙 浠ュ惈绛夊彿銆 褰湞闇 (鍖椾含鑸┖鑸ぉ澶у) MATLAB鍩虹鍙婂伐绋嬪簲鐢 2014 骞 10 鏈 23 鏃 4 / 1 绾挎€ф柟绋嬬粍鐨勮В鏋愯В 绗﹀彿绉垎鍙樻崲 姹傝В涓€鍏冧簩娆℃柟绋媋 * x 2 + b * x + c = 0鐨勮В銆 驴驴 f=sym (鈥檃*x^2+b*x+c=0 鈥?; 驴驴 xf=solve (f) 褰湞闇 (鍖椾含鑸┖鑸ぉ澶у) MATLAB鍩虹鍙婂伐绋嬪簲鐢 2014 骞 10 鏈 23 鏃 5 / 1 绾挎€ф柟绋嬬粍鐨勮В鏋愯В 浠ｆ暟鏂圭▼姹傝В solve 涔熷彲 浠ョ敤鏉ヨВ鏂圭▼缁 solve (鈥檈qn1鈥?鈥檈qn2鈥? 鈥?鈥檈qnN鈥?鈥檝ar1,var2,鈥?varN鈥? 姹傝В鐢扁€檈qn1鈥?鈥檈qn2鈥?鈥?鈥檈qnN鈥 缁勬垚鐨勬柟绋嬬粍鍏充簬鍙橀噺鈥檝ar1,var2,鈥?varN鈥 鐨勮В渚 濡傦細 驴驴 [x ,y ,z]=solve (鈥檟+2*y-z=27 鈥?鈥檟+z=3 鈥? ... 鈥檟^2+3*y^2=28鈥?鈥檟 鈥?鈥檡 鈥?鈥檢 鈥? 杈撳嚭鍙橀噺鐨勯『搴忚涔﹀啓姝ｇ‘ 锛 solve 鍦ㄥ緱涓嶅埌瑙ｆ瀽瑙ｆ椂锛屼細缁欏嚭鏁板€艰В 褰湞闇 (鍖椾含鑸┖鑸ぉ澶у) MATLAB鍩虹鍙婂伐绋嬪簲鐢 2014 骞 10 鏈 23 鏃 6 / 1 绾挎€ф柟绋嬬粍鐨勮В鏋愯В 姹備笅鍒楃嚎鎬т唬鏁版柟绋嬬粍鐨勮В