Q7 of 46 Page 1

Find the relation between x and y such that the points (x, y), (1, 2) and (7, 0) are collinear.

Let A(x, y), B(1, 2) and C(7, 0) be the three collinear points


If the given points are collinear then they will lie on the same line, i.e. they will not form a triangle.


So,


Area of ΔABC = 0


…(i)


Here,


x1 = x, y1 = y, x2 = 1, y2 = 2, x3 = 7 and y3 = 0


Putting the values in eq. (i), we get



⇒ 2x – y + 7y – 14 = 0


⇒ 2x + 6y – 14 = 0


⇒ x + 3y – 7 = 0


∴ x + 3y – 7 = 0 is the required relation between x and y.


More from this chapter

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Find the sum given below:

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 9

Show that is an irrational number, given that 7 is irrational.

OR


Prove that n2 + n is divisible by 2 for any positive integer n.