2分之1根号8-根号0.02+3分之1根号4又2分之1?
=2分之1x2根号2-根号(2/100)+3分之1根号(2分之9)
=根号2-10分之1x根号2+3分之1x3÷根号2
=根号2-10分之1x根号2+1÷根号2
=根号2-10分之1x根号2+根号2÷（根号2）²
=根号2-10分之1x根号2+根号2÷2
=(1-1/10+1/2)x根号2
=(1-0.1+0.5)x根号2
=1.4x1.41
=1.974