解方程log4(3*2^x+7)=log2(2^x+1)

问题描述:

解方程log4(3*2^x+7)=log2(2^x+1)

log4(3*2^x+7)=log2(2^x+1)lg(3*2^x+7)/lg4=lg﹙2^x+1)/lg2lg(3*2^x+7)/2lg2=lg﹙2^x+1)/lg2lg(3*2^x+7)/2=lg﹙2^x+1)√﹙3*2^x+7﹚=2^x+13*2^x+7=﹙2^x+1﹚²3*2^x+7=﹙2^x﹚²+2×2^x+1﹙2^x﹚²-1...