由AB=a,设AP=x,PB=a-x,
两个正方形面积和S=x²+(a-x)²
=x²+a²-2ax+x²
=2x²-2ax+a²
=2(x²-ax+a²/4)+a²-a²/2
=2(x-a/2)²+a²/2
∵2>0,∴S有最小值:
x=a/2时,即P在AB中点,最小值Smin=a²/2.
由AB=a,设AP=x,PB=a-x,
两个正方形面积和S=x²+(a-x)²
=x²+a²-2ax+x²
=2x²-2ax+a²
=2(x²-ax+a²/4)+a²-a²/2
=2(x-a/2)²+a²/2
∵2>0,∴S有最小值:
x=a/2时,即P在AB中点,最小值Smin=a²/2.