Exams Joint Entrance Examination Mathematics Parabola Question 15 Question 15 of 198 Medium MCQ
A line passing through the point A ( − 2 , 0 ) A(-2,0) A ( − 2 , 0 ) , touches the parabola P : y 2 = x − 2 P:{y}^{2}=x-2 P : y 2 = x − 2 at the point B B B in the first quadrant. The area, of the region bounded by the line A B AB A B , parabola P P P and the x x x -axis, is :
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y 2 = 4 ( 1 4 ) ( x − 2 ) y = m ( x − 2 ) + 1 4 m ( − 2 , 0 ) ⇒ 0 = − 4 m + 1 4 m ⇒ 16 m 2 = 1 ⇒ m = ± 1 4 m = 1 4 ⇒ ( 6 , 2 ) \begin{gathered} {y}^{2}=4(\frac{1}{4})(x-2) \\ y=m(x-2)+\frac{1}{4m}(-2,0) \\ \Rightarrow 0=-4m+\frac{1}{4m}\Rightarrow 16{m}^{2}=1 \\ \Rightarrow m=\pm \frac{1}{4} \\ m=\frac{1}{4}\Rightarrow (6,2) \end{gathered} y 2 = 4 ( 4 1 ) ( x − 2 ) y = m ( x − 2 ) + 4 m 1 ( − 2 , 0 ) ⇒ 0 = − 4 m + 4 m 1 ⇒ 16 m 2 = 1 ⇒ m = ± 4 1 m = 4 1 ⇒ ( 6 , 2 )
⇒ = 1 2 × ( 1 ) × 4 + ∫ 6 2 [ ( x + 2 4 ) − x − 2 ] d x = 2 + 2 3 = 8 3 \begin{gathered} \Rightarrow =\frac{1}{2}\times (1)\times 4+{\int }_{6}^{2}[(\frac{x+2}{4})-\sqrt{x-2}]dx \\ \, =2+\frac{2}{3}=\frac{8}{3} \end{gathered} ⇒= 2 1 × ( 1 ) × 4 + ∫ 6 2 [( 4 x + 2 ) − x − 2 ] d x = 2 + 3 2 = 3 8 Answer the question to unlock