Which of the following lines intersects a circle of radius 5 centered at the origin at two points?

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To determine which line intersects the circle of radius 5 centered at the origin at two points, we can start with the equation of the circle:

[ x^2 + y^2 = 25 ]

A line can be expressed in the form ( y = mx + b ), where ( m ) is the slope and ( b ) is the y-intercept. To find the intersection points, we can substitute the equation of the line into the equation of the circle. This will yield a quadratic equation in ( x ).

For the line given in option B, ( y = 2x + 1 ), substituting this into the circle's equation will look like this:

  1. Substitute ( y ) in the circle equation:

[ x^2 + (2x + 1)^2 = 25 ]

  1. Expand and simplify:

[ x^2 + (4x^2 + 4x + 1) = 25 ]

[ 5x^2 + 4x + 1 - 25 = 0 ]

[ 5x^2 + 4x - 24 = 0 ]

3

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