What is the integral of cos^2(x/4) ?

The integral of cos^2(x/4) is 1/2 x+sin(x/2)+C

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

integral of cos^2(x/4)

\int cos^{2} (\frac{x}{4}) d x

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

Solution steps

\int cos^{2} (\frac{x}{4}) d x

Rewrite using trig identities

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

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 (\frac{x}{2}) d x

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 x + \int cos (\frac{x}{2}) d x)

\int 1 d x = x

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

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

Simplify

\frac{1}{2} (x + 2 sin (\frac{x}{2})) : \frac{1}{2} x + sin (\frac{x}{2})

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

Add a constant to the solution

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

What is the integral of cos^2(x/4) ?
The integral of cos^2(x/4) is 1/2 x+sin(x/2)+C