lg5减lg2
来源:学生作业帮助网 编辑:作业帮 时间:2024/05/18 00:19:58
lg5+lg2*lg5+(lg2)^2=(lg2)^2+lg2lg5+lg5=lg2(lg2+lg5)+lg5=lg2*1+lg5=lg5+lg2=lg10=1
(lg2)^2=lg2*lg2(lg2)^2+lg2*lg5+lg5(=lg2*lg2+lg2*lg5+lg5(前两项提取公因式lg2)=lg2(lg2+lg5)+lg5=lg2*1+lg5=1
lg5的平方加2lg2减lg2的平方=(lg5)²+2lg(10/5)-(lg10/5)²=(lg5)²+2-2lg5-(1-lg5)²=(lg5)²+2-2lg5-1-(lg5)²
lg2(lg5-lg2)-lg5(lg5+3lg2)=lg2lg5-(lg2)^2-(lg5)^2-3lg5lg2=-[(lg2)^2+2lg2lg5+(lg5)^2]=-(lg2+lg5)^2=-[lg(2*5)]^2=-1
(lg5)^2+lg2*lg5=lg5(lg5+lg2)=lg5
解(lg5)²+lg5×lg2=lg5×(lg5+lg2)=lg5×1=lg5
原式=lg2+lg2lg5+lg²5=lg2+lg5(lg2+lg5)=lg2+lg5=1
(lg2)^2+lg2*lg5+(lg5)^2=2(lg2)+lg(2+5)+2(lg5)=2(lg2+lg5)+lg7=2lg(2×5)+lg7=2lg10+lg7=2+lg7再问:有lg2*lg5=lg(2+5)公式嗎????!!!是(
原式=(lg5+lg2)²=(lg10)²=1
(lg5)^2+lg5×lg2+lg2=lg5×(lg5+lg2)+lg2=lg5×lg(5×2)+lg2=lg5+lg2=lg(5×2)=lg10=1
注:lg2+lg5=12lg2+2lg5=2(lg2+lg5)=2
lg5^2=lg5+lg5lg5+lg2=1lg5^2+lg2*lg5+lg2=1+lg5+lg2*lg5=1+lg5(1+lg2)=1+lg5(lg20)
(lg2)^3+(lg5)^3+3*lg2*lg5前面用立方和=(lg2+lg5)[(lg2)^2-lg2*lg5+(lg5)^2]+3*lg2*lg5=lg10[(lg2)^2-lg2*lg5+(lg5)^2]+3*lg2*lg5=1*[
g250=lg(10*5^2)=lg10+lg5^2=1+2lg5lg40=lg(10*2^2)=1+2lg2原式=lg2*lg2*(1+2lg5)+lg5*lg5*(1+2lg2)=lg2*lg2+2lg2*lg2*lg5+lg5*lg5
(lg2)³+(lg5)³+3lg2×lg5=(lg2)³+(lg5)³+3lg2×lg5×lg10=(lg2)³+(lg5)³+3lg2×lg5×(lg2+lg5)=(lg2+l
原式=lg5×(lg5+lg2)+lg2=lg5×lg10+lg2=lg5+lg2=lg10=1
=lg22+lg2^2*lg5+lg25=lg22+2*lg2*lg5+lg25=(lg2+lg5)^2=(lg10)^2=1^2=1
2lg5*lg2=2(lg10-lg2)*lg2=2(1-lg2)*lg2=2lg2-2(lg2)^2
原式=2lg5+(2/3)lg8+lg5*lg20+(lg2)^2=2lg5+2lg2+lg5*(lg5+2lg2)+(lg2)^2=2lg5+2lg2+(lg5)^2+2lg2lg5+(lg2)^2=2lg10+(lg5+lg2)^2=2
2lg5+2/3lg8+lg5*lg20+lg2=lg5^2+lg8^(2/3)+lg5*(lg4+lg5)+lg2=lg25+lg4+lg5*(lg4+lg5)+lg2=lg100+lg5*(lg4+lg5)+lg2=lg100+lg5*