Question 233584
cos(x) + sin(x) = 0


They have to be equal with opposite sign so they can cancel each other out.


When x = 45 degrees, sin(x) and cos(x) are the same = .707106781


That's because they're in the first quadrant and sin(x) and cos(x) are both positive because:


opposite = length of the line is always positive.
adjacent is distance on the x-axis to the right of the y-axis and is positive.
opposite is distance on the y-axis up from the x-axis and is positive.


Go to the second quadrant and form 45 degrees up from 180 degrees.
hypotenuse is positive.
adjacent is negative (left of y-axis)
opposite is positive (up from x-axis)


the values are the same but now the sin(x) is positive and cos(x) is negative.


180 - 45 = 135 so we are talking about sin(135) and cos(135).


you get:


sin(135) + cos(135) = 0 because:


.707106781 - .707106781 = 0


Your answer is 135 degrees.