Quadrants
(15 secs)
In which quadrant is θ if
z=-4-4i
?
Quadrant 3
(a,b)->(-4,-4)
The coordinates at 30° are
(\sqrt3/2,1/2)
\theta=tan^-1((-4)/-4)
matches to which what θ-build?
45°
Find
r=\sqrt(a^2+b^2)
if
z=-4-4i
r=\sqrt(32)=4\sqrt2
Find
\theta=tan^-1(b/a)
if
z=-4-4i
\theta=tan^-1((-4)/-4)
θ = 45°-build in Q3
θ = 225°
Convert to rectangular form:
z=\sqrt2[cos(45°)+isin(45°)]
z=\sqrt2[\sqrt2/2 + \sqrt2/2i]=1+i
In which quadrant is θ if
z=4\sqrt3-4i
?
Quadrant 4
(a,b)->(4\sqrt3,-4)
The coordinates at 90° are
(0,1)
\theta=tan^-1((4)/0)
matches to which what θ-build?
90°
Find
r=\sqrt(a^2+b^2)
if
z=4\sqrt3-4i
r=\sqrt(64)=8
Find
\theta=tan^-1(b/a)
if
z=4\sqrt(3)-4i
\theta=tan^-1((-4)/(4\sqrt3))
θ = 30°-build in Q4
θ = 330°
Convert to rectangular form:
z=-[cos((4pi)/2)+isin((4pi)/2)]
z=-1[1 + 0i]=-1+0=-1
In which quadrant is θ if
z=-1/4 + (i\sqrt3)/4
?
Quadrant 2
(a,b)->(-1/4,\sqrt3/4)
The coordinates at -45° are
(\sqrt2/2,-\sqrt2/2)
\theta=tan^-1((-4)/(4\sqrt3))
matches to which what θ-build?
30°
Find
r=\sqrt(a^2+b^2)
if
z=-1/4+(i\sqrt3)/4
r=\sqrt(1/4)=\sqrt(1)/\sqrt(4)=1/2
Find
\theta=tan^-1(b/a)
if
z=-1/4+(i\sqrt3)/4
\theta=tan^-1((\sqrt3/4)/(-1/4))
θ = 60°-build in Q2
θ = 120°
Convert to rectangular form:
z=2/3[cos((7pi)/6)+isin((7pi)/6)]
z=2/3[-\sqrt3/2 - 1/2i]=-\sqrt3/3 -1/3i
The coordinates at
(4\pi)/3
are
(-1/2,-\sqrt 3/2)
\theta=tan^-1((0)/-4)
matches to which what θ-build?
180°
Find
r=\sqrt(a^2+b^2)
if
z=4i
r=\sqrt(16)=4
Find
\theta=tan^-1(b/a)
if
z=4i
\theta=tan^-1(4/0)
(0,b)
θ = 90°
The coordinates at
(4\pi)/6
are
(-1/2, \sqrt3/2)
\theta=tan^-1((\sqrt3/4)/(-1/4))
matches to which what θ-build?
60°
Find
r=\sqrt(a^2+b^2)
if
z=-4
r=\sqrt(16)=4
Find
\theta=tan^-1(b/a)
if
z=-4
\theta=tan^-1(0/-4)
(-a,0)
θ = 180°