Current location - Training Enrollment Network - Mathematics courses - Fourth grade math circle. . . . Kneel for the steps! !
Fourth grade math circle. . . . Kneel for the steps! !
Ordinary points indicate that a straight line is at least tangent to a circle.

The fourth quadrant tangent:

Distance from the center to the tangent point: 2

Because y=x, it can be assumed that the linear equation is y=x+c after translation (because the slope is unchanged, only the intersection of x and y axes is changed).

Because the coordinates of the tangent point are (root number 2,-root number 2), that is, (1.4 14,-1.4 14).

So substitute the tangent point into the equation y = x+c.

-radical number 2 = radical number 2+c

The radical number 2 with C=-2 (2.828)

So y=x-2.828.

So the intersection with the x axis (2.828,0)

Therefore, when the tangent line is in the fourth image limit OP=2.828,

Tangent of the second quadrant:

Similarly, the linear equation can still be obtained as y=x+2.828.

So op is still equal to 2.828 (the actual intersection is (-2.828,0), but considering that op is the distance, it is 2.828).

Therefore, regardless of the translation, the value of OP can only be: 0 to 2.828.