X-component of →a is twice of its Y-component. If the magnitude of the vector is 5√2 and it makes an angle of 135∘ with z-axis then the components of vector is
ax=2ay,cosγ=aza=cos135∘=−1√2
⇒az=−a√2=−5√2√2=−5
Now a2x+a2y+a2z=50⇒4a2y+a2y+25=50
⇒a2y=5⇒ay=±√5⇒ax=±2√5