✔ 最佳答案
Sol
3+√8=3+2√2=[(√2)^2+2*√2*1+1^2]=(√2+1)^2
√(3+√8)=√2+1
x=1/(√2+1)=√2-1
x+1=√2
x^2+2x+1=2
x^2=1-2x
x^4+4x^3+4x^2+4x+3
=(1-2x)^2+4x(1-2x)+4x^2+4x+3
=(4x^2-4x+1)+(-8x^2+4x)+4x^2+4x+3
=4x+4
=4(√2-1)+4
=4√2
log4_(4√2)=log4√2/log4=2log4√2/2log4=log32/4log2=5log2/4log2=5/4