Skip to main contentSkip to solution

∫13xx+4−xdx\displaystyle\int_1^3 \dfrac{\sqrt{x}}{\sqrt{x}+\sqrt{4-x}}dx is equal to:

Solution

✅ Correct Option: 3

Use the property ∫abf(x)dx=∫abf(a+b−x)dx\int_a^b f(x)dx = \int_a^b f(a+b-x)dx with a+b=4a+b = 4.

This gives I=∫134−x4−x+xdxI = \int_1^3 \dfrac{\sqrt{4-x}}{\sqrt{4-x}+\sqrt{x}}dx.

Adding the two forms, 2I=∫131 dx=22I = \int_1^3 1\,dx = 2, so I=1I = 1.

Keyboard Shortcuts

  • Left arrow: Previous question
  • Right arrow: Next question
  • S key: Jump to solution
  • Q key: Jump to question