> 数学 >
函数f(x)=2^x,X1,X2属于R,且X1≠X2,证明:1/2(f(X1)+f(X2))>f((X1+X2)/2)
人气:403 ℃ 时间:2019-10-11 14:07:25
解答
X1≠X2
f(x1)≠f(x2)
1/2(f(X1)+f(X2))-f((X1+X2)/2)
=1/2(2^x1+2^x2)-2^[(x1+x2)/2]
=1/2{2^x1+x^x2-2*2^[(x1+x2)/2]}
=1/2[2^(x1/2)-2^(x2/2)]^2>0
1/2(f(X1)+f(X2))>f((X1+X2)/2)
推荐
猜你喜欢
© 2024 79432.Com All Rights Reserved.
电脑版|手机版