Both the red and blue line segments stretch from center of the circle to a point on the the circle. the length of the blue line segment is 7. how long is the red line segment?

In a quadratic function of the form ax^2+bx+c, which of the following is not true? a. the y-intercept is c. b. if a is positive, the parabola opens up. c. the vertex has an x-coordinate of -b/2a. d. the axis of symmetry is the line y=-b/2a.