Error analysis:
To find the distance between points (2, - 5) and (4, 10) the following steps were used.
Is the distance correct? If the distance is not correct, where was the FIRST mistake made?
Step 1: d =√ (4-2)^2 - (10 + 5)^2
Step 2: d = √ (2)^2 - (15)^2
Step 3: d = √ 4 - 225
Step 4: d = √ -221
Step 5: d = -14.9
A. The distance formula has addition in between the parenthesis, so step 1 should be d = √(4-2)^2 + (10 + 5)^2
B. There are no mistakes. The distance of -14.9 is correct.
C. Step 1 should have (10 - 5)^ 2 as the second parenthesis.
D. In step 2, (15)^2 means multiply 15 times 2 to get 30 instead of 225 for step 3.