show-that-cos-7-1-2-2-3-4-6-

Question Number 46402 by scientist last updated on 25/Oct/18

s h o w t h a t \cos 7 \frac{1}{2} = \sqrt{2} + \sqrt{3} + \sqrt{4} + \sqrt{6}

Commented by Meritguide1234 last updated on 25/Oct/18

i t s h o u l d b e c o t 7 \frac{1}{2}

Answered by ajfour last updated on 25/Oct/18

\cos 15 ° = \sqrt{\frac{1 + \frac{\sqrt{3}}{2}}{2}} = \frac{\sqrt{2 + \sqrt{3}}}{2}

\cos {(\frac{15}{2})}^{°} = \sqrt{\frac{1 + \frac{\sqrt{2 + \sqrt{3}}}{2}}{2}}

= \frac{\sqrt{2 + \sqrt{2 + \sqrt{3}}}}{2} .

Facebook Tweet Pin