设a,b,c∈R,且c≠0,求证:(a+b)²≤(1+c²)a²+(1+1/c²)b²

来源:学生作业帮助网 编辑:作业帮 时间:2024/07/12 16:37:11
设a,b,c∈R,且c≠0,求证:(a+b)²≤(1+c²)a²+(1+1/c²)b²
x){n_NN򣎎 ';$?\`lcӋz#Q;N5eCs GK".P< #$ ,"}[_`gC'hӝggd@@8#{B$ ԁ<\ \ĤZ`5A@+ @ßӲ

设a,b,c∈R,且c≠0,求证:(a+b)²≤(1+c²)a²+(1+1/c²)b²
设a,b,c∈R,且c≠0,求证:(a+b)²≤(1+c²)a²+(1+1/c²)b²

设a,b,c∈R,且c≠0,求证:(a+b)²≤(1+c²)a²+(1+1/c²)b²
(1+c^2)a^2+(1+1/c^2)b^2
=a^2+b^2+a^2c^2+b^2/c^2
≥a^2+b^2+2·|ac|·|b/c|
=a^2+b^2+2|ab|
≥a^2+b^2+2ab
=(a+b)^2