MHT CET202521 Apr 2025Morning ShiftMathematicsArea Under CurvesActual
The area inside the parabola y^2=4 a x , between the lines x=a and x=4 a is equal to
Options
- A4 a^2 sq. units
- B8 a^2 sq. units
- C56 a^2 3 sq. units
- D35 a^2 3 sq. units
Correct answer
C. 56 a^2 3 sq. units
Step-by-step solution
Area inside the parabola y^2 = 4ax between x = a and x = 4a . The parabola y^2 = 4ax is symmetric about the x-axis, with the upper half given by y = 2 ax . The total area is twice the area above the x-axis, so we compute A = 2 _a^ 4a 2 ax dx = 4 a _a^ 4a x dx . Evaluating the integral: 4 a [ 2 3 x^ 3/2 ]_a^ 4a = 8 a 3 ( (4a)^ 3/2 - a^ 3/2 ) . Simplifying: (4a)^ 3/2 = 8a^ 3/2 , so A = 8 a 3 (8a^ 3/2 - a^ 3/2 ) = 8 a 3 7a^ 3/2 = 56 3 a^2 . This corresponds to option C : 56a^2 3 square units.