What is the integral from 0 to 1 of 1/(x^2-x+1) ?

The integral from 0 to 1 of 1/(x^2-x+1) is (2pi)/(3sqrt(3))

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

integral from 0 to 1 of 1/(x^2-x+1)

\int_{0}^{1} \frac{1}{x ^{2} - x + 1} d x

\frac{2 π}{3 3}

Decimal

1.20919 \dots

Solution steps

\int_{0}^{1} \frac{1}{x ^{2} - x + 1} d x

Complete the square

x^{2} - x + 1 : (x - \frac{1}{2})^{2} + \frac{3}{4}

= \int_{0}^{1} \frac{1}{( x - \frac{1}{2} ) ^{2} + \frac{3}{4}} d x

Apply u-substitution

= \int_{- \frac{1}{2}}^{\frac{1}{2}} \frac{4}{4 u ^{2} + 3} d u

Take the constant out:

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

= 4 \cdot \int_{- \frac{1}{2}}^{\frac{1}{2}} \frac{1}{4 u ^{2} + 3} d u

Apply Integral Substitution

= 4 \cdot \int_{- \frac{1}{3}}^{\frac{1}{3}} \frac{1}{2 3 ( v ^{2} + 1 )} d v

Take the constant out:

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

= 4 \cdot \frac{1}{2 3} \cdot \int_{- \frac{1}{3}}^{\frac{1}{3}} \frac{1}{v ^{2} + 1} d v

Use the common integral:

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

= 4 \cdot \frac{1}{2 3} [arctan (v)]_{- \frac{1}{3}}^{\frac{1}{3}}

Simplify

4 \cdot \frac{1}{2 3} [arctan (v)]_{- \frac{1}{3}}^{\frac{1}{3}} : \frac{2}{3} [arctan (v)]_{- \frac{1}{3}}^{\frac{1}{3}}

= \frac{2}{3} [arctan (v)]_{- \frac{1}{3}}^{\frac{1}{3}}

Compute the boundaries:

\frac{π}{3}

= \frac{2}{3} \cdot \frac{π}{3}

Simplify

= \frac{2 π}{3 3}

What is the integral from 0 to 1 of 1/(x^2-x+1) ?
The integral from 0 to 1 of 1/(x^2-x+1) is (2pi)/(3sqrt(3))