So the question is asking to determine all points of intersection, and base on my research and further computation about the said question, the possible answer would be y=cos(x), sin(x)=cos(x), sin2(x)=cos2(x), sin2(x)=1−sin2(x), sin2(x)+sin2(x)=1, 2sin2(x)=1, sin2(x)=1/2, sin(x)=√1/2, sin(x)=√2/2. I hope this would help
