Question
Solve the equation
c1=318×ic2=−23612−2318ic3=23612−2318i
Alternative Form
c1≈2.620741ic2≈−2.269629−1.310371ic3≈2.269629−1.310371i
Evaluate
5c3i=90
Multiply the numbers
5ic3=90
Divide both sides
5i5ic3=5i90
Divide the numbers
c3=5i90
Divide the numbers
More Steps

Evaluate
5i90
Multiply by the Conjugate
5i×i90i
Calculate
More Steps

Evaluate
5i×i
Multiply
5i2
Use i2=−1 to transform the expression
5(−1)
Calculate
−5
−590i
Rewrite the expression
−55×18i
Cancel out the common factor 5
−118i
Calculate
−18i
c3=−18i
Simplify
c=3−18i
Rewrite the complex number in polar form
More Steps

Evaluate
−18i
Determine the modulus and the argument of the complex number
r=02+(−18)2θ=arctan(0−18)
Calculate
More Steps

Evaluate
02+(−18)2
Calculate
0+(−18)2
Add the numbers
324
Write the number in exponential form with the base of 18
182
Reduce the index of the radical and exponent with 2
18
r=18θ=arctan(0−18)
Substitute the given values into the formula r(cosθ+isinθ)
18(cos(23π)+isin(23π))
c=318(cos(23π)+isin(23π))
Calculate the nth roots of a complex r(cos(θ)+i×sin(θ),using nz=nr(cosnθ+2kπ+isinnθ+2kπ)
c=318×(cos(323π+2kπ)+isin(323π+2kπ))
Since n=3,substitute k=0,1,2 into the expression
c1=318×(cos(323π+2×0×π)+isin(323π+2×0×π))c2=318×(cos(323π+2×1×π)+isin(323π+2×1×π))c3=318×(cos(323π+2×2π)+isin(323π+2×2π))
Calculate
More Steps

Evaluate
323π+2×0×π
Any expression multiplied by 0 equals 0
323π+0
Removing 0 doesn't change the value,so remove it from the expression
323π
Multiply by the reciprocal
23π×31
Reduce the numbers
2π×1
Multiply the numbers
2π
c1=318×(cos(2π)+isin(2π))c2=318×(cos(323π+2×1×π)+isin(323π+2×1×π))c3=318×(cos(323π+2×2π)+isin(323π+2×2π))
Calculate
More Steps

Evaluate
323π+2×1×π
Multiply the terms
323π+2π
Calculate
More Steps

Evaluate
23π+2π
Reduce fractions to a common denominator
23π+22π×2
Write all numerators above the common denominator
23π+2π×2
Multiply the terms
23π+4π
Add the numbers
27π
327π
Multiply by the reciprocal
27π×31
To multiply the fractions,multiply the numerators and denominators separately
2×37π
Multiply the numbers
67π
c1=318×(cos(2π)+isin(2π))c2=318×(cos(67π)+isin(67π))c3=318×(cos(323π+2×2π)+isin(323π+2×2π))
Calculate
More Steps

Evaluate
323π+2×2π
Multiply the terms
323π+4π
Calculate
More Steps

Evaluate
23π+4π
Reduce fractions to a common denominator
23π+24π×2
Write all numerators above the common denominator
23π+4π×2
Multiply the terms
23π+8π
Add the numbers
211π
3211π
Multiply by the reciprocal
211π×31
To multiply the fractions,multiply the numerators and denominators separately
2×311π
Multiply the numbers
611π
c1=318×(cos(2π)+isin(2π))c2=318×(cos(67π)+isin(67π))c3=318×(cos(611π)+isin(611π))
Solution
c1=318×ic2=−23612−2318ic3=23612−2318i
Alternative Form
c1≈2.620741ic2≈−2.269629−1.310371ic3≈2.269629−1.310371i
Show Solution
