Find the values of y for which the distance between the points P(2, – 3) and Q(10, y) is 10 units?
It is given that the distance between (2,-3) and (10,y) is 10.
Therefore, \(\sqrt{(2-10)^2+(-3-y)^2}=10\)
\(\sqrt{(-8)^2+(3+y)^2}=10\)
\(64+(y+3)^2=100\)
\((y+3)^2=36\)
\(y+3=\pm 6\)
\(y+3=6\) or \(y+3=-6\)
Therefore, \(y=3\) or \(-9\)
Determine if the points (1, 5), (2, 3) and (– 2, – 11) are collinear
In a classroom, 4 friends are seated at points A, B, C and D. Champa and Chameli walk into the class and after observing for a few minutes Champa asks Chameli, “Don’t you think ABCD is a square?” Chameli disagrees. Using the distance formula, find which of them is correct.
| Case No. | Lens | Focal Length | Object Distance |
|---|---|---|---|
| 1 | \(A\) | 50 cm | 25 cm |
| 2 | B | 20 cm | 60 cm |
| 3 | C | 15 cm | 30 cm |