What is the integral of sqrt(-x^2+2x) ?

The integral of sqrt(-x^2+2x) is 1/2 (arcsin(x-1)+1/2 sin(2arcsin(x-1)))+C

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

integral of sqrt(-x^2+2x)

\int - x^{2} + 2 x d x

\frac{1}{2} (arcsin (x - 1) + \frac{1}{2} sin (2 arcsin (x - 1))) + C

Solution steps

\int - x^{2} + 2 x d x

Complete the square

- x^{2} + 2 x : - (x - 1)^{2} + 1

= \int - (x - 1)^{2} + 1 d x

Apply u-substitution

= \int - u^{2} + 1 d u

Apply Trigonometric Substitution

= \int cos^{2} (v) d v

Rewrite using trig identities

= \int \frac{1 + cos ( 2 v )}{2} d v

Take the constant out:

\int a \cdot f (x) d x = a \cdot \int f (x) d x

= \frac{1}{2} \cdot \int 1 + cos (2 v) d v

Apply the Sum Rule:

\int f (x) \pm g (x) d x = \int f (x) d x \pm \int g (x) d x

= \frac{1}{2} (\int 1 d v + \int cos (2 v) d v)

\int 1 d v = v

\int cos (2 v) d v = \frac{1}{2} sin (2 v)

= \frac{1}{2} (v + \frac{1}{2} sin (2 v))

Substitute back

= \frac{1}{2} (arcsin (x - 1) + \frac{1}{2} sin (2 arcsin (x - 1)))

Add a constant to the solution

= \frac{1}{2} (arcsin (x - 1) + \frac{1}{2} sin (2 arcsin (x - 1))) + C

What is the integral of sqrt(-x^2+2x) ?
The integral of sqrt(-x^2+2x) is 1/2 (arcsin(x-1)+1/2 sin(2arcsin(x-1)))+C