For the first Question:The answer is (e).
basically means that the value is a negative version of cos(
). Because up till
the values for cos are positive, as it is in the ALL quadrant. However, this does not lie in that quadrant, so it is negative version of
.
For the second question:The only answer is (c).
or
(I like working in degrees)
Remembering the sin wave, by making the equation
, you put two sin waves into the 0 to 360 gap. Therefore, where 360 degrees was, that position is 180 degrees. Therefore, if we repeat the wave, we repeat the values. Therefore
degrees is also an answer.
So, the two answers are:
and
The working without the explanation is as follows:
Therefore,
and
45 degrees is equal to
radians and 225 degrees is equal to
Hope this clears all doubts.