Find $| \mathrm { v } |$ and $| \mathbf { u } + \mathbf { y } |$
, given that $\mathbf { u } = - \mathbf { j }$
And $\mathbf { v } = \mathbf { i }$
A) $| \mathrm { v } | = 1$
, $| \mathbf { u } + \mathrm { v } | = \sqrt { 2 }$
B) $| v | = - 1$
, $| \mathbf { u } + \mathbf { v } | = - \sqrt { 2 }$
C) $| \mathrm { v } | = \sqrt { 2 }$
, $| \mathbf { u } + \mathbf { y } | = 1$
D) $| \mathrm { v } | = \sqrt { 2 }$
, $| \mathbf { u } + \mathrm { v } | = \sqrt { 2 }$
E)none

Question

Quizplus · Accepted Answer

Since $\mathbf { u } = - \mathbf { j }$, then $| \mathbf { u } | = |- \mathbf { j }| = 1$. 
And since $\mathbf { v } = \mathbf { i }$, then $| \mathrm { v } | = | \mathbf { i } | = 1$.  
So, $|\mathbf{u}+\mathbf{v}|=|-\mathbf{j}+\mathbf{i}|=$ $ \sqrt { ( -1 ) ^ { 2 } + ( -1 ) ^ { 2 }  }$ $=\sqrt { 2 }$

Find ∣v∣| \mathrm { v } |∣v∣ And ∣u+y∣| \mathbf { u } + \mathbf { y } |∣u+y∣

Find $| \mathrm { v } |$ And $| \mathbf { u } + \mathbf { y } |$