23 . D
The expression (1 − 2x)^2 is something squared. A real number squared cannot be smaller
than 0. This function will have its minimum value when the part inside the parentheses is
zero:
24 . A
If the two lines are perpendicular, then their slopes are negative reciprocals.
The slope of y = 2x + 5 is 2, so the slope of the other line is . That line goes through the
origin, so its y-intercept is 0, and therefore its equation is . Point P—the
intersection of these lines—is the point that satisfies both equations:
So point P is (−2,1), and the distance from the origin to point P is
25 . A
Set the formulas equal and solve for :
