对于两个实数a,b,我们规定一种新运算*:a*b=4ab。无论*为何值,总有a*x=x,求a的值
a\u3001b\u4e3a\u5b9e\u6570\uff0c\u73b0\u89c4\u5b9a\u4e00\u79cd\u65b0\u7684\u8fd0\u7b97a@b=a*b-a/b\uff0c\u5219\u5f53(x+2)@2=6\u65f6\uff0cx\u7684\u503c\u662f\u591a\u5c11\uff1f\u4ee3\u5165\u6cd5\uff1a\u628aa=x+2\uff0cb=2\u4ee3\u5165\u65b0\u8fd0\u7b97\u516c\u5f0fa@b=a*b-a/b\u5f972(x+2)-(x+2)/2=6\uff0c\u6574\u7406\u5f97\uff1a3(x+2)=12\uff0c\u89e3\u5f97x=2
(ab)^2+a^2+b^2+1-4ab=0
(ab)^2-2ab+1+a^2+b^2-2ab=0
(ab-1)^2+(a-b)^2=0
\u6240\u4ee5ab-1=0,a-b=0
a=b=1 or -1
∴4ax=x
当x=0时,a我任意实数
当x≠0时,a=1/4
根据定义的运算可得:a*x=4ax=x,方程两边消去x既得a=1/4.
0.25吧
绛旓細1銆瀵逛簬涓や釜瀹炴暟a銆b锛屾垜浠瀹氫竴绉嶆柊杩愮畻鈥*鈥濓紱a*b=4ab銆傦紙1锛夎В鏂圭▼锛3*x-2*4=0 (1) 4脳3x锛4脳2脳4锛0 12x-32锛0 12X=32 X=3/8 3銆佸皬鏉庨獞鑷杞︿粠A鍦板埌B鍦帮紝灏忔槑楠戣嚜琛岃溅浠嶣鍦板埌A鍦帮紝涓や汉閮藉寑閫熷墠杩涳紝宸茬煡涓や汉鍦ㄤ笂鍗8鏃跺嚭鍙戯紝鍒颁笂鍗10鏃讹紝涓や汉杩樼浉璺36鍗冪背锛屽埌涓崍12鏃...
绛旓細(x+2)*4-(1+2)*x=10 4x+8-3x=10 x+8=10 x=2
绛旓細a*x=4ax 鈭4ax=x 褰搙=0鏃讹紝a鎴戜换鎰瀹炴暟 褰搙鈮0鏃讹紝a=1/4
绛旓細5*(-3)=3*5*(-3)=-45
绛旓細涔熷氨鏄棤璁篨涓哄悎鍊锛孉*X=4AX=X 閭d箞4AX=X瑕佹垚绔嬶紝涓よ竟鍚屾椂绾︽帀X 4A=1锛鎵浠=1/4鏃堕璁炬垚绔
绛旓細杩欎釜绠鍗曪紝鍙鈥滀箻娉曗濊繍绠楄繕鏄師鏉ョ殑鎰忔濓細a*x=4ax=x 浜庢槸4a=1 浜庢槸a=1/4
绛旓細瑙o細(1)鍥5^3=125锛屾墍浠=5 (2)鈶狅紙2,4锛+锛2,8锛夌瓑浜庯紙2,2^5锛夆憽锛3,9锛+锛3,27锛夌瓑浜庯紙3,3^5锛夆憿锛4,16锛+锛4,64锛夌瓑浜庯紙4,4^5锛夆懀锛5,25锛+锛5,125锛夌瓑浜庯紙5,5^5锛(3)褰ab=d鏃讹紝婊¤冻锛a锛宐锛+锛坅锛宒锛=锛坅锛宔锛夋弧鎰忔垜鐨勫洖绛旀暚璇烽噰绾筹紝O(鈭鈭)O璋㈣阿 ...
绛旓細瀵逛簬浠绘剰瀹炴暟x1銆亁2,鎴戜滑瑙勫畾min{x1銆亁2}琛ㄧずx1,x2涓殑杈冨皬鑰,鑻(x)=2x+3,g(x)=鈥4x鈥9.姹(1)min{f(x),g(x)}鐨勮В鏋愬紡銆(2)min{f(x),g(x)}鐨勬渶澶у笺... 瀵逛簬浠绘剰瀹炴暟x1銆亁2,鎴戜滑瑙勫畾min{x1銆亁2}琛ㄧずx1,x2涓殑杈冨皬鑰,鑻(x)=2x+3,g(x)=鈥4x鈥9.姹(1)min{f(x),g...
绛旓細a鈻b=1/(a+b)a鈽哹=b/(a²-b²)m鈻硁+2(m鈽唍)=1/(m+n)+2n/(m²-n²)=(m-n+2n)/(m+n)(m-n)=1/(m-n)=1/(2012-2013)=-1
绛旓細a鈥伙紙a+b锛-a鈥籦 =1鈥(1-2)-1鈥(-2)=1鈥(-1)-1鈥(-2)=[2脳1脳(-1)-1-1]-[2脳1脳(-2)-1-2]=(-2-1-1)-(-4-1-2)=(-4)-(-7)=3