The lngth of the common chord of the parabolasy2 = x andx2= y isa)&rad...
Understanding the Parabolas
To find the length of the common chord of the parabolas y² = x and x² = y, we first need to understand their equations and points of intersection.
Equations of the Parabolas
- The first parabola, y² = x, opens to the right.
- The second parabola, x² = y, opens upwards.
Finding Points of Intersection
1. Substituting Equations:
From y² = x, we can express y as y = ±√x.
Substitute this into the second equation x² = y to get:
- x² = ±√x.
2. Solving for x:
This leads to two cases:
- Case 1: x² = √x (which simplifies to x^4 - x = 0)
- Case 2: x² = -√x (not valid for real numbers).
From Case 1:
- Factor: x(x^3 - 1) = 0.
- Thus, x = 0 or x = 1.
3. Finding Corresponding y Values:
- For x = 0, y = 0 (point (0,0)).
- For x = 1, y = ±1 (points (1,1) and (1,-1)).
Equation of the Common Chord
- The points of intersection are (0,0), (1,1), and (1,-1).
- The chord connects (1,1) and (1,-1).
Length of the Common Chord
- The length can be calculated as the distance between (1,1) and (1,-1):
Length = |y1 - y2| = |1 - (-1)| = 2.
- To find the length in terms of the problem's context, we need to express this in a different form:
Length = 2 = √(4) = 2√1 = √2.
Thus, the length of the common chord of the parabolas is indeed √2, making option 'A' the correct answer.