若a的平方加a减1等于0
来源:学生作业帮助网 编辑:作业帮 时间:2024/04/24 06:45:10
a的平方减4a加1等于0a-4+1/a=0a+1/a=4
a^2+3a+1=0a^2+1=-3a都除以a可得a+1/a=-3a^2+1/a^2=(a+1/a)^2-2=9-2=7a^2-2+1/a^2=7-2=5所以a-1/a=√5
因为 a^2--3a+1=0所以 a--3+1/a=0a+1/a=3a^2+2+1/a^2=9a^2+1/a^2=7所以 (a^4+a^2+1)/a^2=a^2+1+1/a^2=a^2+1/a^2+1
a^2-3a+1=0a^2+1=3aa+1/a=3a^2+1/a^2=a^2+2+1/a^2-2=(a+1/a)^2-2=3^2-2=7
应是a^2+a-1=0a的立方+3倍a的平方+a-4=a*(a^2+3a+1)-4=a*(1-a+3a+1)-4=a*(2+2a)-4=2*(a+a^2)-4=2*1-4=-2
=[√(a^2-1)+√(1-a^2)]/(a+7)+4√(a^2-1)>=0a^2>=1a>=-1或a=0-1
√(a^2-2a+1)=0√(a-1)^2=0(a-1)^2=0a=1
a^2-3a+1=0a^2+1=-3aa+1/a=-3(a+1/a)^2=9展开后得到a^2+1/a^2=9-2=7
A的平方加3A加1等于0a^2+3a+1=0A的4次方加3A的3次方减A的平方减5A加A分之一减二的值a^4+3a^3-a^2-5a+1/a-2因为a^2+3a+1=0所以a^2+3a=-1a^2+3
因为a*a-2a+b*b+6b+10=(a-1)*(a-1)+(b+3)*(b+3)=0(a-1)*(a-1)>=0;(b+3)*(b+3)>=0.所以a=1,b=-3.
a²+a-1=0(a³+2a²-6)/(a²+a)=[a(a²+a)+a²-6)]/(a²+a)=(a+a²-6)/(a
a^2-√10a+1=0a^2+1=√10a两边除aa+1/a=√10两边平方a^2+2*a*1/a+1/a^2=10a^2+2+1/a^2=10a^2+1/a^2=8
a^2-2a+1+b^2+6b+9=0(a-1)^2+(b+3)^2=0a=1 b=-31^2011-(-1/3)=4/3
已知A^2-5A+1=0,求A^2+1/A^2.(^2表示平方的意思)在已知的两边同时除以A,得A-5+1/A=0A+1/A=5上式两边同平方,得(A+1/A)^2=25展开,得A^2+1/A^2+2
a^2-5a+1=0a^2+1=5aa+1/a=5(a+1/a)^2=a^2+1/a^2+2=25a^2+1/a^2=23
(ab)^2+a^2+b^2+1-2ab=2ab(ab)^2+(a-b)^2+1-2ab=0ab(ab-2)+(a-b)^2+1=0a=-1,b=-1a+b=-2
∵a²-a-1=0∴a²=a+1∴a²+1/a²=(a+1)+1/(a+1)=(a²+2a+2)/(a+1)=(a+1+2a+2)/(a+1)=3
由已知(1/4*a²-a+1)+(9b²+12b+4)=0,即(1/2*a-1)²(3b+2)²=0,由非负数的性质,得1/2*a-1=0,且3b+2=0,所以
a²+5a-1=0a+5-1/a=0∴a-1/a=-5两边平分得a²-2+1/a²=25∴a²+1/a²=27