Question 306812
We are in quadrant 1 because the angle given is positive.

Drop a perpendicular line from the terminal side of the angle creating a right triangle.

At the origin, we know that the angle is 45 degrees as given. When we drop a line from the terminal to the x-axis, we make 90 degrees where the line that is dropped meets the x-axis.  This means the we have a 45-45-90 degree right triangle.


This tells me, from the unit circle that you should memorize (it will make your entire trig journey so much easier) that the value of the hypotenuse is 2 and the two legs of the right triangle are square root 2.

sine = opposite side/hypotense

Then sine = sqrt{2}/2

cosine = adjacent side/hypotenuse

Then cosine = sqrt{2}/2