int_(0)^1f^2(x)dxleqslantint_(0)^1xdxcdotint_(0)^1f^prime(}^2(t)dt=(1)/(2)int_{0)^1f^prime{}^2(t)dt.注 本题若再加一个条件f(1)=0,便可证明int_(0)^1f^2(x)dxleqslant(1)/(4)int_(0)^1f^prime(}^2(x)dx及int_{0)^1f^2(x)dxleqslant(1)/(8)int_(0)^1f^prime{}^2(x)dx.

$\int_{0}^{1}f^{2}(x)dx\leqslant\int_{0}^{1}xdx\cdot\int_{0}^{1}f^{\prime}{}^{2}(t)dt=\frac{1}{2}\int_{0}^{1}f^{\prime}{}^{2}(t)dt.$ 注 本题若再加一个条件f(1)=0,便可证明 $\int_{0}^{1}f^{2}(x)dx\leqslant\frac{1}{4}\int_{0}^{1}f^{\prime}{}^{2}(x)dx$及$\int_{0}^{1}f^{2}(x)dx\leqslant\frac{1}{8}\int_{0}^{1}f^{\prime}{}^{2}(x)dx.$

参考答案与解析:

相关试题

(4)已知 (x)=(int )_(1)^x(e)^-(t^2)dt, 则 (int )_(0)^1f(x)dx=

(4)已知 (x)=(int )_(1)^x(e)^-(t^2)dt, 则 (int )_(0)^1f(x)dx=

  • 查看答案
  • [2019数学二](13)已知函数f(x)=xint_(1)^x(sin t^2)/(t)dt,则int_(0)^1f(x)dx=____

    [2019数学二](13)已知函数f(x)=xint_(1)^x(sin t^2)/(t)dt,则int_(0)^1f(x)dx=____[2019数学二](1

  • 查看答案
  • 设f(x)连续,且 (x)=x+2(int )_(0)^1f(t)dt, 则 f(x)= __

    设f(x)连续,且 (x)=x+2(int )_(0)^1f(t)dt, 则 f(x)= __

  • 查看答案
  • 【例4】已知函数f(x)在[-1,2]上连续,且int_(-1)^0f(x)dx=2,int_(0)^1f(2x)dx=1,则int_(-1)^2f(x)dx=()

    【例4】已知函数f(x)在[-1,2]上连续,且int_(-1)^0f(x)dx=2,int_(0)^1f(2x)dx=1,则int_(-1)^2f(x)dx=

  • 查看答案
  • 2.(2020山东高数Ⅲ)已知函数f(x)在[-1,2]上连续,且int_(-1)^0f(x)dx=2,int_(0)^1f(2x)dx=1,则int_(-1)^2f(x)dx=()

    2.(2020山东高数Ⅲ)已知函数f(x)在[-1,2]上连续,且int_(-1)^0f(x)dx=2,int_(0)^1f(2x)dx=1,则int_(-1)

  • 查看答案
  • 设 f ( x ) 是连续奇函数且(int )_(0)^1f(x)dx=-2 则 (int )_(0)^1f(x)dx=-2

    设 f ( x ) 是连续奇函数且(int )_(0)^1f(x)dx=-2 则 (int )_(0)^1f(x)dx=-2设f(x)是连续奇函数且则

  • 查看答案
  • 设(x)=dfrac (1)(1+{x)^2}+sqrt (1-{x)^2}(int )_(0)^1f(x)dx, 则 (int )_(0)^1f(x)dx=

    设(x)=dfrac (1)(1+{x)^2}+sqrt (1-{x)^2}(int )_(0)^1f(x)dx, 则 (int )_(0)^1f(x)dx=设

  • 查看答案
  • 25.f(x)在[0,1]上连续,在(0,1)内可导,且 (int )_(0)^1f(t)dt=0, 证明:存在 xi in (0,1) 使得 (xi )=(int )_(0)^5f(t)dt.

    25.f(x)在[0,1]上连续,在(0,1)内可导,且 (int )_(0)^1f(t)dt=0, 证明:存在 xi in (0,1) 使得 (xi )=(i

  • 查看答案
  • [题目]设f(x)是连续函数,且 (x)=x+2(int )_(0)^1f(t)dt,-|||-则 f(x)= __

    [题目]设f(x)是连续函数,且 (x)=x+2(int )_(0)^1f(t)dt,-|||-则 f(x)= __

  • 查看答案
  • (B) (int )_(-1)^1f(x)dxlt 0.-|||-(C) (int )_(-1)^0f(x)dxgt (int )_(0)^1f(x)dx. (D) (int )_(-1)^0f(x)

    (B) (int )_(-1)^1f(x)dxlt 0.-|||-(C) (int )_(-1)^0f(x)dxgt (int )_(0)^1f(x)dx. (

  • 查看答案