use reference angle to find the exact value of the expression, do not use a calculator cos 225 degrees

TallGuy asked Aug 13, 2023

413,241 views

21 votes

TallGuy asked Aug 13, 2023

3.0k points

Your comment on this question:

Email me at this address if a comment is added after mine:Email me if a comment is added after mine

Privacy: Your email address will only be used for sending these notifications.

Email me at this address if my answer is selected or commented on:Email me if my answer is selected or commented on

Privacy: Your email address will only be used for sending these notifications.

8 votes

To find

$\cos 225^o$

Now,

$\begin{gathered} \cos 225^o=\cos (180^o+45^o)^{} \\ =\cos (2*90^o+45^o) \\ =-\cos 45^o \\ =-\frac{1}{\sqrt[]{2}} \end{gathered}$

So, the required value is

$-\frac{1}{\sqrt[]{2}}$

BAR answered Aug 17, 2023

by BAR

2.9k points

Email me at this address if a comment is added after mine:Email me if a comment is added after mine

Privacy: Your email address will only be used for sending these notifications.

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

1.6m questions

2.0m answers