Acounterexample for the expression sin(x)+cos(x)=1 is 45° true or false?

For this case we have the following expression:
 sin (x) + cos (x) = 1
 Substituting x = 45 degrees we have:
 sin (45) + cos (45) = 1
 (root (2) / 2) + (root (2) / 2) = 1
 Rewriting:
 (root (2) + root (2)) / 2 = 1
 (2 * root (2)) / 2 = 1
 root (2) = 1
 We observe that the equation is not fulfilled.
 
 Yes, A counterexample for the expression sin (x) + cos (x) = 1 is 45 °.
 TRUE

The answer maybbe c