1. SOLUTION EXAMPLE 4 Standardized Test Practice Use the Distance Formula. You may find it helpful to draw a diagram.

2. EXAMPLE 4 Standardized Test Practice Distance Formula Substitute. Subtract. Evaluate powers. Add. Use a calculator to approximate the square root. (x – x ) + (y – y ) 2 2 2 21 1 RS= [(4 – 2)] + [(–1) –3] 22 = (2) + (–4 ) 22 = 4+16 = 20 = 4.47 = The correct answer is C. ANSWER

3. GUIDED PRACTICE for Example 4 5. In Example 4, does it matter which ordered pair you choose to substitute for (x, y ) and which ordered pair you choose to substitute for (x, y ) ? Explain. 1 2 1 2 No, when squaring the difference in the coordinate you get the same answer as long as you choose the x and y value from the some period ANSWER

4. GUIDED PRACTICE for Example 4 6. What is the approximate length of AB, with endpoints A(–3, 2) and B(1, –4)? 6.1 units 7.2 units 8.5 units 10.0 units Distance Formula Substitute. Subtract. (x – x ) + (y – y ) 2 2 2 21 1 AB = [2 –(–3)] + (–4 –1) 2 2 = (5) + (5 ) 22 = Use the Distance Formula. You may find it helpful to draw a diagram. SOLUTION

5. GUIDED PRACTICE for Example 4 Evaluate powers. Add. Use a calculator to approximate the square root. 25+25 = 50 = 7.2 = The correct answer is BANSWER