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Find all of the fifth roots of the complex number 4+32i.  Put your answers in the rectangular form a+bi and in the polar form z=re(iΘ).  Please show how you got to your answers.

 Nov 24, 2015

Best Answer 

 #2
avatar+1904 
+10

(4+32i)(1/5)

 

r=(a2+b2)

 

r=(42+322)

 

r=(16+1024)

 

r=1040

 

r=465

 

tan(Θ)=b/a

 

tan(Θ)=32/4

 

tan(Θ)=8

 

Θ=tan1(8)

 

Θ1.4464413322481

 

 

z=re(iΘ)

 

z465e(i1.4464413322481)

 

z(1/5)(465e(i1.4464413322481))(1/5)

 

z(1/5)(465)(1/5)e(i1.4464413322481(1/5))

 

z(1/5)2.003103242348e(i1.0766143512748)

 

z=r(cos(Θ)+isin(Θ))

 

z2.003103242348(cos(1.0766143512748)+isin(1.0766143512748))

 

z2.003103242348(0.4743116564868+i0.88035700289064)

 

z0.9500952169545+i1.763445966914

 

z0.9500952169545+1.763445966914i

 

 

z(1/5)(465e(i7.7296266394277))(1/5)

 

z(1/5)(465)(1/5)e(i7.7296266394277(1/5))

 

z(1/5)2.003103242348e(i1.5459253278855)

 

z=r(cos(Θ)+isin(Θ))

 

z2.003103242348(cos(1.5459253278855)+isin(1.5459253278855))

 

z2.003103242348(0.024868434927217+i0.99969073264899)

 

z0.049814942634829+i0.0001545372385216

 

z0.049814942634829+0.0001545372385216i

 

 

z(1/5)(465e(i14.012811946607))(1/5)

 

z(1/5)(465)(1/5)e(i14.012811946607(1/5))

 

z(1/5)2.003103242348e(i1.6955283616309)

 

z=r(cos(Θ)+isin(Θ))

 

z2.003103242348(cos(1.6955283616309)+isin(1.6955283616309))

 

z2.003103242348(0.12440885450163+i0.99223104009177)

 

z0.24920377983349+i1.9875412136019

 

z0.24920377983349+1.9875412136019i

 

 

z(1/5)(465e(i20.2959972538))(1/5)

 

z(1/5)(465)(1/5)e(i20.2959972538(1/5))

 

z(1/5)2.003103242348e(i4.059994507574)

 

z=r(cos(Θ)+isin(Θ))

 

z2.003103242348(cos(4.05994507574)+isin(4.05994507574))

 

z2.003103242348(0.60772245598411+i0.7941494925344)

 

z1.2173308220295+i1.5907634234047

 

z1.2173308220295+1.5907634234047i

 

 

z(1/5)(465e(i26.5918256098))(1/5)

 

z(1/5)(465)(1/5)e(i26.5918256098(1/5))

 

z(1/5)2.003103242348e(i5.315836512196)

 

z=r(cos(Θ)+isin(Θ))

 

z2.003103242348(cos(5.315836512196)+isin(5.315836512196))

 

z2.003103242348(0.56748448302716+i0.82338409112843)

 

z1.1367300079339+i1.6493233426371

 

z1.1367300079339+1.6493233426371i

 

z1.13673000793391.6493233426371i

.
 Nov 26, 2015
 #1
avatar
+5

z = (4 + 32i)^(1/5)  

Divide: 1 / 5 =0.2

Power: (4+32i) ^ 0.2 = 1.9198686+0.5714255i


Algebraic form:
z = 1.9198686+0.5714255i

Exponential form:
z = 2.0031032 × ei 16°34'30″

Trigonometric form:
z = 2.0031032 × (cos 16°34'30″ + i sin 16°34'30″)

Polar form:
r = |z| = 2.0031
φ = arg z = 16.575° = 16°34'30″ = 0.09208π

 Nov 24, 2015
 #2
avatar+1904 
+10
Best Answer

(4+32i)(1/5)

 

r=(a2+b2)

 

r=(42+322)

 

r=(16+1024)

 

r=1040

 

r=465

 

tan(Θ)=b/a

 

tan(Θ)=32/4

 

tan(Θ)=8

 

Θ=tan1(8)

 

Θ1.4464413322481

 

 

z=re(iΘ)

 

z465e(i1.4464413322481)

 

z(1/5)(465e(i1.4464413322481))(1/5)

 

z(1/5)(465)(1/5)e(i1.4464413322481(1/5))

 

z(1/5)2.003103242348e(i1.0766143512748)

 

z=r(cos(Θ)+isin(Θ))

 

z2.003103242348(cos(1.0766143512748)+isin(1.0766143512748))

 

z2.003103242348(0.4743116564868+i0.88035700289064)

 

z0.9500952169545+i1.763445966914

 

z0.9500952169545+1.763445966914i

 

 

z(1/5)(465e(i7.7296266394277))(1/5)

 

z(1/5)(465)(1/5)e(i7.7296266394277(1/5))

 

z(1/5)2.003103242348e(i1.5459253278855)

 

z=r(cos(Θ)+isin(Θ))

 

z2.003103242348(cos(1.5459253278855)+isin(1.5459253278855))

 

z2.003103242348(0.024868434927217+i0.99969073264899)

 

z0.049814942634829+i0.0001545372385216

 

z0.049814942634829+0.0001545372385216i

 

 

z(1/5)(465e(i14.012811946607))(1/5)

 

z(1/5)(465)(1/5)e(i14.012811946607(1/5))

 

z(1/5)2.003103242348e(i1.6955283616309)

 

z=r(cos(Θ)+isin(Θ))

 

z2.003103242348(cos(1.6955283616309)+isin(1.6955283616309))

 

z2.003103242348(0.12440885450163+i0.99223104009177)

 

z0.24920377983349+i1.9875412136019

 

z0.24920377983349+1.9875412136019i

 

 

z(1/5)(465e(i20.2959972538))(1/5)

 

z(1/5)(465)(1/5)e(i20.2959972538(1/5))

 

z(1/5)2.003103242348e(i4.059994507574)

 

z=r(cos(Θ)+isin(Θ))

 

z2.003103242348(cos(4.05994507574)+isin(4.05994507574))

 

z2.003103242348(0.60772245598411+i0.7941494925344)

 

z1.2173308220295+i1.5907634234047

 

z1.2173308220295+1.5907634234047i

 

 

z(1/5)(465e(i26.5918256098))(1/5)

 

z(1/5)(465)(1/5)e(i26.5918256098(1/5))

 

z(1/5)2.003103242348e(i5.315836512196)

 

z=r(cos(Θ)+isin(Θ))

 

z2.003103242348(cos(5.315836512196)+isin(5.315836512196))

 

z2.003103242348(0.56748448302716+i0.82338409112843)

 

z1.1367300079339+i1.6493233426371

 

z1.1367300079339+1.6493233426371i

 

z1.13673000793391.6493233426371i

gibsonj338 Nov 26, 2015

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