肉片土豆做法大全家常:求对数答案

来源:百度文库 编辑:查人人中国名人网 时间:2024/05/09 07:11:08
lg((3+(5)^(1/2))^(1/2)+(3-(5)^(1/2))^(1/2))=?
lg5*lg8000+(lg2^(3^(1/2)))^2+lg(1/6)+lg0.006=?

(1)
令t=(3+(5)^(1/2))^(1/2)+(3-(5)^(1/2))^(1/2)
=√(3+√5)+√(3-√5)
所以t^2=3+√5+3-√5+√(3+√5)(3-√5)
=6+2
=8
t=√8(t>0)
lg((3+(5)^(1/2))^(1/2)+(3-(5)^(1/2))^(1/2))
=lgt=lg√8

(2)
lg5*lg8000+(lg2^(3^(1/2)))^2+lg(1/6)+lg0.006
=lg5*(3lg2+3)+3(lg2)^2+lg1-lg6-3+lg6
=3lg5*lg2+3lg5+3(lg2)^2-3
=3lg5*lg2+3(lg2)^2+3lg5-3
=3lg2*(lg5+lg2)+3lg5-3
=3lg2+3llg5-3
=3(lg2+lg5)-3
=3-3
=0

若正棱锥的底面边长与侧棱长相等,则该棱锥一定不是:(...(25)解方程lg(x2+4x-26)-lg(x-3)=1。...x=3+时,原方程的左边=lg10-lg=lg10=1=右边...

大哥我只查到了这么点,不好意思!~