数学 每日一题(第二十六天)
$1.已知a=\dfrac{1}{2}\sqrt{\sqrt{2}+\dfrac{1}{8}}-\dfrac{\sqrt{2}}{8},$
$求代数式a^2+\sqrt{a^4+a+1}的值.$
$2.已知非零实数a,b,c满足\dfrac{1}{a}+\dfrac{2}{b}+\dfrac{3}{c}=0,$
$求代数式\dfrac{3b+2c}{6a}+\dfrac{2c+6a}{3b}+\dfrac{6a+3b}{2c}的值.$
$3.已知实数a,b,c满足(a+b+c)(\dfrac{1}{a}+\dfrac{1}{b}+\dfrac{1}{c})=1,$
$求证:\dfrac{1}{(a+b+c)^{2027}}=\dfrac{1}{a^{2027}}+\dfrac{1}{b^{2027}}+\dfrac{1}{c^{2027}}.$
$4.实数a,b,x,y满足:$
$ax+by=3$
$ax^2+by^2=7$
$ax^3+by^3=16$
$ax^4+by^4=42$
$求ax^5+by^5的值.$
$5.已知非零实数a,b,c满足a+b+c=0,求:$
$(1)(\dfrac{a-b}{c}+\dfrac{b-c}{a}+\dfrac{c-a}{b})(\dfrac{c}{a-b}+\dfrac{a}{b-c}+\dfrac{b}{c-a});$
$(2)\dfrac{a^5+b^5+c^5}{abc(ab+bc+ca)}.$
共1条回复
时间正序