If the polar coordinates of the vector are (r,theta)(r,θ), then
The components are (rcostheta,rsintheta)(rcosθ,rsinθ) in the rectangular cordinates are
x=rcosthetahatix=rcosθˆi
y=rsinthetahatjy=rsinθˆj
Here, we have
(r,theta)=(4,11/12pi)(r,θ)=(4,1112π)
x=4cos(11/12pi)=4cos(2/3pi+1/4pi)x=4cos(1112π)=4cos(23π+14π)
=4(cos(2/3pi)cos(1/4pi)-sin(2/3pi)sin(1/4pi))=4(cos(23π)cos(14π)−sin(23π)sin(14π))
=4(-1/2*sqrt2/2-sqrt3/2*sqrt2/2)=4(−12⋅√22−√32⋅√22)
=-4/4(sqrt2+sqrt6)=−44(√2+√6)
=-(sqrt2+sqrt6)=−(√2+√6)
y=4sin(11/12pi)=4sin(2/3pi+1/4pi)y=4sin(1112π)=4sin(23π+14π)
=4(sin(2/3pi)*cos(1/4pi)+cos(2/3pi)*sin(1/4pi))=4(sin(23π)⋅cos(14π)+cos(23π)⋅sin(14π))
=4*(sqrt3/2*sqrt2/2-1/2*sqrt2/2)=4⋅(√32⋅√22−12⋅√22)
=(sqrt6-sqrt2)=(√6−√2)
The vector is
=-(sqrt2+sqrt6)hati+(sqrt6-sqrt2)hatj=−(√2+√6)ˆi+(√6−√2)ˆj