1.

The value of y for which distance between points P(2, 3) and Q(0, y) is 10 unit, is :(A) -9 or -3(B) 9 or -3(C) 9 or 3(D) -4 or 9

Answer»

Answer is (B) 9 or -3

Distance between P(2, 3) and Q(10, y) = 10

√((10 - 2)2 + (y - 3)2) = 10

square both sides

⇒ (8)2 + (y – 3)2 = 100

⇒ (y – 3)2 = 100 – 64

⇒ (y – 3)2 = 36

⇒ y – 3 = ±6

Taking the +ve sign

y – 3 = 6

y = 6 + 3 = 9

Taking -ve sign

y – 3 = -6

y = -6 + 3 = -3

So y = 9 or -3



Discussion

No Comment Found

Related InterviewSolutions