Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section A

Chapter

Application of Integrals

Question:

Find the area bounded by the curves y = -x2 + 6x -5, y = -x2 + 4x - 3 and the straight line y = 3x - 15.

Options:

$\frac{22}{3}$

$\frac{73}{6}$

$\frac{5}{3}$

None of these

Correct Answer:

$\frac{73}{6}$

Explanation:

The two parabolas can be re-written as and C1:

(x - 3)2 = -(y - 4) cut - axis at points noted (1, 0), (5, 0)

C2 : (x - 2)2 = -(y - 1) cut - axis at points noted (1, 0), (3, 0)

L: y = 3x -15 cut x-axis at points noted (5, 0)

(1, 0) is the common point of P1 and P2, (5, 0) is the common point of C1 and L and C2 and L meet at (4, -3).

Required area is : $\int\limits_1^4C_1dx-[\int\limits_1^4C_2dx+\int\limits_4^5l\,dx]$

Solve to get area = $\frac{73}{6}$