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Let the equations of the sides PQ, QR, R...

Let the equations of the sides PQ, QR, RS and SP of a quadrilateral PQRS are `x+2y-3=0, x-1=0, x-3y-4=0` and `5x+y+12=0` respectively. If `theta` is the angle between the diagonals PR and QS, then the value of `|tan theta|` is equal to

A

2

B

`-2`

C

1

D

Not defined

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To find the value of \(|\tan \theta|\) where \(\theta\) is the angle between the diagonals \(PR\) and \(QS\) of the quadrilateral \(PQRS\), we will follow these steps: ### Step 1: Identify the equations of the sides The equations of the sides of the quadrilateral are given as: - \(PQ: x + 2y - 3 = 0\) - \(QR: x - 1 = 0\) - \(RS: x - 3y - 4 = 0\) - \(SP: 5x + y + 12 = 0\) ### Step 2: Find the intersection points to determine the vertices of the quadrilateral We need to find the points \(P\), \(Q\), \(R\), and \(S\) by solving the equations of the lines. #### Finding Point Q: From \(QR: x - 1 = 0\), we have \(x = 1\). Substituting \(x = 1\) into \(PQ: x + 2y - 3 = 0\): \[ 1 + 2y - 3 = 0 \implies 2y = 2 \implies y = 1 \] Thus, \(Q(1, 1)\). #### Finding Point R: Substituting \(x = 1\) into \(RS: x - 3y - 4 = 0\): \[ 1 - 3y - 4 = 0 \implies -3y = 3 \implies y = -1 \] Thus, \(R(1, -1)\). #### Finding Point P: Now, we will find \(P\) by solving \(PQ\) and \(SP\). We already have \(PQ: x + 2y - 3 = 0\) and \(SP: 5x + y + 12 = 0\). From \(PQ: x + 2y - 3 = 0\), we can express \(y\) in terms of \(x\): \[ 2y = 3 - x \implies y = \frac{3 - x}{2} \] Substituting this into \(SP\): \[ 5x + \frac{3 - x}{2} + 12 = 0 \] Multiplying through by 2 to eliminate the fraction: \[ 10x + 3 - x + 24 = 0 \implies 9x + 27 = 0 \implies x = -3 \] Substituting \(x = -3\) back into \(PQ\) to find \(y\): \[ -3 + 2y - 3 = 0 \implies 2y = 6 \implies y = 3 \] Thus, \(P(-3, 3)\). #### Finding Point S: Now, we will find \(S\) by solving \(RS\) and \(SP\): Using \(RS: x - 3y - 4 = 0\): \[ x = 3y + 4 \] Substituting into \(SP: 5x + y + 12 = 0\): \[ 5(3y + 4) + y + 12 = 0 \implies 15y + 20 + y + 12 = 0 \implies 16y + 32 = 0 \implies y = -2 \] Substituting \(y = -2\) back into \(RS\): \[ x - 3(-2) - 4 = 0 \implies x + 6 - 4 = 0 \implies x = -2 \] Thus, \(S(-2, -2)\). ### Step 3: Find the slopes of the diagonals PR and QS Now we have the points: - \(P(-3, 3)\) - \(Q(1, 1)\) - \(R(1, -1)\) - \(S(-2, -2)\) #### Slope of diagonal PR: \[ m_{PR} = \frac{y_2 - y_1}{x_2 - x_1} = \frac{-1 - 3}{1 - (-3)} = \frac{-4}{4} = -1 \] #### Slope of diagonal QS: \[ m_{QS} = \frac{y_2 - y_1}{x_2 - x_1} = \frac{-2 - 1}{-2 - 1} = \frac{-3}{-3} = 1 \] ### Step 4: Calculate \(|\tan \theta|\) The formula for the tangent of the angle \(\theta\) between two lines with slopes \(m_1\) and \(m_2\) is given by: \[ \tan \theta = \left| \frac{m_1 - m_2}{1 + m_1 m_2} \right| \] Substituting \(m_{PR} = -1\) and \(m_{QS} = 1\): \[ \tan \theta = \left| \frac{-1 - 1}{1 + (-1)(1)} \right| = \left| \frac{-2}{1 - 1} \right| \] Since the denominator becomes zero, this means that the lines are perpendicular, and thus \(\theta = 90^\circ\). Therefore, \(|\tan \theta| = \infty\). ### Final Answer The value of \(|\tan \theta|\) is \(\infty\).
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