Say I know the x and y components, how do i go about finding the diagonal one?

[teggenspiller]

Homework Statement

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If my y component is 120m/s and my X component is 50m/s, how do I go about finding initial V??


Attempt:

i know that the y component = sin(O)*V
and the x= cos (O) *V

So that must mean that
V= x/cos(O)
AND
V= y/sin(O)

so maybe just maybe: x/cos(O)=y/sin(O)

But i don't know theta. and I am not looking for it either.
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[gneill]

A vector with perpendicular components x and y has magnitude sqrt(x² + y²).