I am trying to find the magnitude of a resultant vector. Do i take inconsideration the negatives when i find the x & y components of the two vectors

Absolutely! If you have two vectors with equal magnitudes and opposite

directions, then one of them is the negative of the other. Their correct

vector sum is zero, and that's exactly the magnitude of the resultant vector.

(Think of fifty football players pulling on each end of the rope in a tug-of-war.

Their forces are equal in magnitude but opposite in sign, and the flag that

hangs from the middle of the rope goes nowhere, because the resultant

force on it is zero.)

This gross, messy explanation is completely applicable when you're totaling up

the x-components or the y-components.