Chapter 7 · Question 1

State the distance formula between two points (x1,y1)(x_1,y_1) and (x2,y2)(x_2,y_2).

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Q1

State the distance formula between two points (x1,y1)(x_1,y_1) and (x2,y2)(x_2,y_2).

Answer Revealed
Direct Answer:
The distance is d=(x2x1)2+(y2y1)2d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}.

Simple Explanation

Use the horizontal difference and vertical difference as the legs of a right triangle.

Exam-Ready Structure

The distance formula comes from Pythagoras theorem. If A(x1,y1)A(x_1,y_1) and B(x2,y2)B(x_2,y_2), then horizontal distance is x2x1|x_2-x_1| and vertical distance is y2y1|y_2-y_1|. Therefore AB=(x2x1)2+(y2y1)2AB=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}.

Key Points

  • The distance is d=(x2x1)2+(y2y1)2d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}.
  • Use the NCERT formula or theorem carefully.
  • Write units and final conclusion where applicable.