Question

题:边长为1的正方形OABC的顶点O为坐标原点．点A在x轴的正半轴上．点C在y轴的正半轴上．动点D在线段BC上移动(不与

Answer 1

let BE=x,thus AE=1-x

DE^2=x^2+(1-T）^2

OE^2=x^2+（1-T）^2

DO^2=1+T^2

as DE^2+DO^2=OE^2

x^2+(1-T)^2+1+T^2=1+（1-x)^2

x=T-T^2

s=(BE+CO)/2=(t-t^2+1)/2=-0.5*(t-0.5)^2+0.625

So,when t=0.5 ,s│max=0.625