EduFarming
Your list · 0हिं

Type at least two letters. Press Esc to close.

↑↓ navigate↵ openTAB cycle filter

Indefinite Integrals · Question 58 of 90

Question 58

HardOriginal question

Evaluate ∫dx3+2x−x2\int \frac{dx}{\sqrt{3 + 2x - x^{2}}}.

Options for question 58

Show the answer and explanation
CorrectNot quiteAnswer A

Correct answer: A

Explanation

  1. Complete the square: 3+2x−x2=4−(x−1)23 + 2x - x^{2} = 4 - (x - 1)^{2}.

  2. ∫dx22−(x−1)2=sin⁡−1x−12+C\int \frac{dx}{\sqrt{2^{2} - (x - 1)^{2}}} = \sin^{-1}\frac{x - 1}{2} + C.

Worth noting

12\frac{1}{2} in front belongs to ∫dxx2+a2\int \frac{dx}{x^{2} + a^{2}}; ∫dxa2−u2=sin⁡−1ua\int \frac{dx}{\sqrt{a^{2} - u^{2}}} = \sin^{-1}\frac{u}{a} has no such factor.

Concept
Completing the square under a root
Typical time
120 s
Your time
—
The rule this testsIntegrals of particular functions
Practise this chapter →

Ten questions from Indefinite Integrals, at your own pace.

Practise this chapter →

Ten questions from Indefinite Integrals, at your own pace.