Math Problem Statement

solve z the poer of 3/2 equals to 5i

Solution

We are given the equation:

z32=5iz^{\frac{3}{2}} = 5i

To solve for zz, we need to isolate zz by raising both sides of the equation to the power of 23\frac{2}{3}. This will reverse the effect of raising zz to the power of 32\frac{3}{2}.

Step 1: Raise both sides to the power of 23\frac{2}{3}

(z32)23=(5i)23\left( z^{\frac{3}{2}} \right)^{\frac{2}{3}} = (5i)^{\frac{2}{3}}

On the left-hand side, (z32)23\left( z^{\frac{3}{2}} \right)^{\frac{2}{3}} simplifies to zz, so we have:

z=(5i)23z = (5i)^{\frac{2}{3}}

Step 2: Simplify (5i)23(5i)^{\frac{2}{3}}

To compute (5i)23(5i)^{\frac{2}{3}}, it's helpful to express 5i5i in polar form. The complex number 5i5i has a magnitude of 5 and an argument of π2\frac{\pi}{2} (since it's purely imaginary and points along the positive imaginary axis).

So, we can express 5i5i as: 5i=5eiπ25i = 5 \cdot e^{i\frac{\pi}{2}}

Now, we compute (5i)23(5i)^{\frac{2}{3}} by raising the polar form to the power of 23\frac{2}{3}:

(5i)23=(5eiπ2)23=523ei23π2=523eiπ3(5i)^{\frac{2}{3}} = \left( 5 \cdot e^{i\frac{\pi}{2}} \right)^{\frac{2}{3}} = 5^{\frac{2}{3}} \cdot e^{i\frac{2}{3} \cdot \frac{\pi}{2}} = 5^{\frac{2}{3}} \cdot e^{i\frac{\pi}{3}}

Step 3: Final Answer

Thus, the solution for zz is:

z=523eiπ3z = 5^{\frac{2}{3}} \cdot e^{i\frac{\pi}{3}}

This represents a complex number in polar form. We can convert this back into rectangular form (a + bi) if needed, but this is the general solution.

Would you like me to express it in rectangular form, or do you have any other questions about this solution?

Related Questions:

  1. How do we convert complex numbers from polar to rectangular form?
  2. What is the significance of the argument of a complex number in this type of problem?
  3. How do we solve equations involving roots of complex numbers?
  4. What is the geometric interpretation of raising a complex number to a fractional power?
  5. How do we find all solutions to equations like this that involve complex numbers?

Tip: When dealing with complex numbers, the polar form is often the easiest way to work with powers and roots, especially when the argument is a simple fraction of π\pi.

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Math Problem Analysis

Mathematical Concepts

Complex Numbers
Polar Form of Complex Numbers
Fractional Powers of Complex Numbers

Formulas

z^{3/2} = 5i
(z^{3/2})^{2/3} = (5i)^{2/3}
5i = 5 * e^{iπ/2}
(5i)^{2/3} = 5^{2/3} * e^{iπ/3}

Theorems

Polar Form of Complex Numbers
De Moivre's Theorem
Roots of Complex Numbers

Suitable Grade Level

Grades 11-12