How do you find the exact value of cos 7pi/4?
3 Answers
Explanation:
Evaluate
So
Now divide
That means
First, convert to degrees (for many people, these are more convenient to work with).
Explanation:
The conversion factor between radians and degrees is
Now, this is a special angle, which can be found by using the special triangles.
But first, we must determine the reference angle of
We now know that we must use the
Now, it's just a matter of applying the definition of cos to find the wanted trig ratio.
Hopefully this helps!
Explanation:
Trig unit circle and trig table -->