How do you find the exact value of tan 405 degrees?

1 Answer
Jun 11, 2018

tan405=1

Explanation:

On the unit circle, the nearest x-axis to 405 degrees is 360 degrees. This means the reference angle (difference between the two) is 45 degrees.

What do we know about 45 degrees?

The coordinates are (22,22)

where the x coordinate is the cos value and the y coordinate is the sin value. We understand tanθ to be defined as

sinθcosθ

Thus, we have 2222, which simplifies to 1.

We found tan45, which is the same as tan405 because 45 degrees is its reference angle.

tan405=1

Hope this helps!