Let P((π)/(4)), Q ((5 π)/(4)), R((3 π)/(4)), T((7 π)/(4)) be the...
Let P(4π),Q(45π),R\left(\frac{3 \pi}{4}\right),T(47π)bethepointsonthehyperbolax^2-4 y^2-4=0intheparametricform.ThentheareaofthequadrilateralP Q R T is (in square units)
Options
A42
B162
C322
D82
Correct answer
D. 82
Step-by-step solution
Equation of hyperbola x2−4y2−4=04x2−1y2=1 Then, a=2,b=1 Parametric point on hyperbola =(asecθ,btanθ) Then, \mathrm{P}\left(\frac{\pi}{4}\right)= \left(2 \sec \left(\frac{\pi}{4}\right),1 \tan \left(\frac{\pi}{4}\right)\right) =(2 \sqrt{2}, 1) Similarly, Q \left(\frac{5 \pi}{4}\right)=\left(2 \sec \left(\frac{5 \pi}{4}\right), 1 \tan \left(\frac{5 \pi}{4}\right)\right) and =(−22,1) and R(43π)=(−22,−1) and T(47π)=(22,−1) Area of quadrilateral PQRT(sq. unit) and =21{(x1−x3)(y2−y4)−(x2−x4)(y1−y3)} and =21{(22+22)(1+1)−(−22−22)(1+1)} and =21{42×2+42×2} and =21×162=82So, option (d) is correct.