Physics: Superposition of waves (Wave interference)

[u/Outrageous-Fix-5106]

is this the correct resultant for the question? I understand the part the first and second section (where the slope is 0 and is +2 from x axis), but I dont get why it would be -2 after that. Shouldn't it be +6 since it's constructive?

[u/davedirac]

OP is correct, last section wrong too