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The 3 cube roots of a cubic equation are often going to require complex numbers, and this is one of them. The primary root is (-2) since (-2)3= -8 The other two roots are going to have the same mod (2) but be evenly spaced around the complex plane, so (2pi)/3 angular difference.
These angles are pi/3 and 5pi/3
(2,pi/3) = (1 + √3i) = (1 + 1.732i)
(2,5pi/3) = (1 + -√3i) = (1- 1.732i)
Check
(-2)3 = -8◄
(1 + √3i)3 = -8◄
(1 - √3i)3 = -8◄
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What are three cube roots of 8?
The cubic root of 8 = 2 2 * 2 * 2 = 8
What is the definition of a cube root?
The cube root for a real number is the value that when multiplied by itself three times produces that number. So that the cube root of B is A where A x A x A = B.Examplesthe cube root of 8 is 2... (2x2x2=8)the cube root of 27 is 3...(3x3x3=27)The special cases are 0 and 1, which are by definition their own roots (square roots, cube roots, etc.) because all powers of 0 and 1 are still the same value, zero or 1.Perfect cubes are numbers that can be cube-rooted into an integer.These include the numbers 0, 1, 8, 27, and so forth.Negative numbers can also be perfect cubes.-1x-1x-1=-1-2x-2x-2=-8-3x-3x-3=-27For non-perfect cubes, the root includes a repeating decimal requiring rounding.
Why does a cube root only have one value?
Because the cube of a positive number is positive and the cube of a negative number is negative.-------------------------------------------------------------------------------------------------------------------------------Every number has THREE cube roots. However, (at least) two of the three are complex numbers.For example, the cube roots of 8 are 2, (-1 + √3 i) and (-1 - √3 i) with i² = -1:2³ = 2 × 2 × 2 = 8(-1 + √3 i)³ = (-1 + √3 i)(-1 + √3 i)(-1 + √3 i)= (-1 + √3 i)((-1)² - 2√3 i + 3i²)= (-1 + √3 i)(1 - 2√3 i -3)= (-1 + √3 i)(-2 - 2√3 i)= (-1 + √3 i)(-1 - √3 i)2= ((-1)² - 3i²)2= (1 + 3)2= 4 × 2 = 8(-1 - √3 i)³ = (-1 - √3 i)(-1 - √3 i)(-1 - √3 i)= (-1 - √3 i)((-1)² + 2√3 i + 3i²)= (-1 - √3 i)(1 + 2√3 i -3)= (-1 - √3 i)(-2 + 2√3 i)= (-1 - √3 i)(-1 + √3 i)2= ((-1)² - 3i²)2= (1 + 3)2= 4 × 2 = 8
Which part of a cube is a vertex?
A vertex of a cube is its corner points. A cube has 8 vertices and six faces. It also has 12 edges. A cube is a three-dimensional figure.
Square root of 64 then cube it?
The square root of 64 is 8. When you cube 8, you multiply it by itself three times, which equals 512. So, the cube of the square root of 64 is 512.
