Rationalizing the denominator and expressing a fraction as a surd

**Coach** · September 9th 2007, 09:00 AM

I'm sorry about the stupid questions, I just don't understand this.

Express these in surd form and rationalize the denominators

a)
$\frac{1}{1+cos45}$

Thank you so much!

**Jhevon** · September 9th 2007, 09:05 AM

Originally Posted by Coach

I'm sorry about the stupid questions, I just don't understand this.

express these in surd form and rationalize the denominators

a)
$\frac{1}{1+cos45}$

you should know that $\cos 45^{\circ} = \frac {\sqrt {2}}{2}$

so, $\frac {1}{1 + \cos 45} = \frac {1}{1 + \frac {\sqrt {2}}{2}}$

$= \frac {1}{\frac {2 + \sqrt {2}}{2}}$

$= \frac {2}{2 + \sqrt {2}}$

Now we need to rationalize this. I don't want to do all the work for you, so i'll tell you what to do.

multiply by the conjugate of the base ( $2 - \sqrt {2}$ ) over itself, and simplify

Thread: Rationalizing the denominator and expressing a fraction as a surd

LinkBack

Thread Tools

Display

Rationalizing the denominator and expressing a fraction as a surd

Similar Math Help Forum Discussions

Rationalizing Denominator

Rationalizing the Denominator

Rationalizing the Denominator

Rationalizing the Denominator

Rationalizing a Denominator

Search Tags