Two adjacent sides of a parallelogram are 4x + 5y = 0 and 7x + 2y = 0.
If the equation of one of the diagonals is 11x + 7y = 4, find the equation
of the other diagonal.
If the question is "Two adjacent sides of a parallelogram are 4x + 5y = 0 and 7x + 2y = 0. If the equation of one of the diagonals is 11x + 7y = 9, find the equation of the other diagonal", then the solution is given below:
Let AB and AD be consecutive sides of parallelogram ABCD having equations 4x + 5y = 0 and 7x + 2y = 0 respectively. These 2 lines intersect at A(0, 0).
11x + 7y = 9
4x + 5y = 0
On solving, we get
Thus, coordinates of B are .
Similarly
11x + 7y = 9
7x + 2y = 0
On solving, we get the coordinates of D.
Thus, D =
Since diagonals of a parallelogram bisect each other, therefore, P is the mid-point of BD. The coordinates of P are .
Hence, equation of AC is
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