Use a special triangle on the unit circle to determine the value of cos π/ 4 .

A) 1

B) 1 /2

C) √2/ 2

D) √2 /3

Question

Use a special triangle on the unit circle to determine the value of cos π/ 4 .

A) 1

B) 1 /2

C) √2/ 2

D) √2 /3

AZ · Answer

Do you know what a unit circle is?

AZ · Answer

$\dfrac{\pi}{4}$ is in radians but it's equal to 45 degrees

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AZ · Answer

If the hypotenuse is 1,

what are the two legs of the triangle?

You can use Pythagorean theorem to calculate the value of 'x'

since both angles are 45 that means they both have the same length

AZ · Answer

if you don't want to do all that work, you can just look at the unit circle I attached and see what the value of cos(pi/4) is

Foreverangel · Answer

I believe it is C?

AZ · Answer

That is correct

Foreverangel · Answer

Thank you

AZ · Answer

You're welcome!