sin \(\theta\) = cos \(\theta\) 0 \(\leq\) \(\theta\) \(\leq\) 360o The acute angle where sin \(\theta\) = cos \(\theta\) = 45o But at the third Quadrant Cos \(\theta\) = -ve; sin \(\theta\) = -ve. at the 3rd quadrant, value with respect to Q is (180 + Q) where Q = acute angle (180 + 45) = 225^\circ The two solution are 45^\circ, 225^\circ