Thursday

August 21, 2014

August 21, 2014

Posted by **Justin** on Sunday, May 23, 2010 at 11:18pm.

I'm not sure how I use euler's formula to solve for this. A brief explanation would be greatly appreciated.

- calculus -
**drwls**, Monday, May 24, 2010 at 7:12amDoes the "x" indicate multiplication, or is it an unknown? Does the 4 multi-ply (3^1/3) - 4i or just 3^(1/3) ?

Find the magnitude of the complex number first. Call it C. Then write your number as

C*e^(i*z)

using Euler's formula.

e^iz = cos z + i sin z

The magnitude of

-4 *(3^1/3 - 4i)

is

4*sqrt[3^(2/3) + 16] = 17.01

so you can write

-4 *(3^1/3 - 4i)

= 17.01*(-0.3392 +0.9406 i)

Now find the number z (in radians) for which

cos z = -0.3392 and sinz = 0.9406

It will be in the second quadrant

z = 1.9169

The answer would be 17.01 exp(1.9169i),

but it depends upon whether I interpreted what you wrote correctly. You need to use parenthese and explain the "x"

- calculus -
**Justin**, Monday, May 24, 2010 at 8:49pmSorry for the misunderstanding. The X is a multiplication sign and the 4 is multiplied to the cubed root of 3.

**Related Questions**

calculus - Write the complex number in exponential form. i i is the complex ...

Calculus - Why can't a equal 1 in y=log(base a) x. And why is x always positive ...

pre-calculus - find the complex zeros of the polynomial function. write F in the...

Pre-Calculus - How would I write this in exponential form? log(3)1/27= -3

Calculus - In these complex exponential problems, solve for x: 1)e^(i*pi) + 2e^(...

Algebra Help - Let x = log_2 1/8 Write the exponential form of the equation and ...

Calc - how do I solve this arcsin(4/5) note that I am not looking for about 53 ...

trigonometry - 1)Solve and write in standard form: 4x^2-4x+21=0 2)Find the ...

Math - Use the quadratic formula to solve each of the following quadratic ...

algebra - Find the complex zeros of the polynomial function. Write f in factored...