There is a ship full of goods. The goods on the water are 6 meters wide and 4.4 meters high. Can he cross a semicircular arch bridge with a diameter of 10 m? "

Set the water surface just at the maximum diameter of the semi-circular arch bridge, take the water surface as the X axis and the center of the arch bridge as the origin, and establish the coordinate system. The circular equation of this arch bridge is: x? +y？ =25

According to the known, as long as the point p (3,4.4) is not greater than the radius of the circle:

Because of 3? +4.4? = 28.36 >； 25

It is outside the circle, so when the horizontal plane is on the diameter line of the arch bridge, it can't pass the semicircular arch bridge with the diameter of 10 meter.

Another: 5? -3? =4?

So as long as the water surface is 0.4 meters below the horizontal line of the arch bridge diameter, the ship can pass.