Question

What is the value of cos(pi/4)?

Answer 1

`sqrt2/2`

Explanation:

As you can see in the table above, `cos45^@` or `cospi/4` radians is the same thing as `sqrt2/2`

An alternative way is looking at the unit circle:

We know that the cosine of an angle is the `x`-value of a coordinate. At `pi/4`, we can see that the `x`-value is `sqrt2/2`.

Therefore, `cos(pi/4) = sqrt2/2`

Hope this helps!