# Calculus

I have a problem about complex number.

Let z=7e^(7*pi*i/4) .

Write z, z^4, z^7, z^(-2) in the form a + b i

I have no idea how to do it. Any hints will be appreciated.

1. 👍 0
2. 👎 0
3. 👁 150
asked by Kelly
1. z=7e^(7*pi*i/4)

z^4 = 7^4 e^(7*pi*i)

And then you use that
e^(i theta) = cos(theta) + i sin(theta)

1. 👍 0
2. 👎 0

## Similar Questions

1. ### Math

Write the following complex number in polar form. Express all angles in degrees rounded to the nearest tenth. Given complex number: 5+6i

asked by Narancia Ghirga on June 13, 2019
2. ### Math clarification Reiny

This is the problem you helped me with. I was curious, do I write the solution set as (1 + i3ã3)/2, (1-i3ã3)/2 change it to the standard form first x^2 - x + 7 = 0 a=1, b=-1, c = 7 x = (1 } ã(1 - 4(1)(7))/2 = (1 }

asked by Sabrina on September 25, 2010
3. ### Math Reiny question

This is the problem you helped me with. I was curious, do I write the solution set as (1 + i3ã3)/2, (1-i3ã3)/2 change it to the standard form first x^2 - x + 7 = 0 a=1, b=-1, c = 7 x = (1 } ã(1 - 4(1)(7))/2 = (1 }

asked by Sabrina on September 24, 2010
4. ### Algebra 2

Write the expression as a complex number in standard form. 3-3i/4i I'm not sure about this problem, but I think the answer is -3/4i-3/4. Could anyone help me please?

asked by Jennie on December 8, 2011
5. ### Chemistry

Write the formula for a complex formed between Ni 2+ and NH3, with a coordination number of 5. Write the formula for a complex formed between Ni 2+ and CN–, with a coordination number of 4. I am having trouble with these problem

asked by Sophie on June 1, 2014
6. ### Pre-Calculus

Hello! I'm stuck on how to do this problem and would appreciate some help! Choose a non-zero complex number c for f(z) = z2+ c. Find a complex number v that is in the escape set. Find a complex number w that is in the prisoner

asked by Anonymous on May 18, 2012
7. ### Pre-Calc

Hello! I'm stuck on how to do this problem and would appreciate some help! Choose a non-zero complex number c for f(z) = z2+ c. Find a complex number v that is in the escape set. Find a complex number w that is in the prisoner

asked by l on May 17, 2012
8. ### calculus

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

asked by Miranda on May 30, 2010
9. ### Trig/Precalc

The system of equations: |z-2-2i|=sqrt(23), |z-8-5i|=sqrt(38) has two solutions z_1 and z_2 in complex numbers. Find (z_1+z_2)/2. My first instinct on this problem was to square each equation given that the square of the magnitude

asked by majorbill on February 16, 2015
10. ### math

Number of apartments rented The manager of an 80 unit apartment complex knows from experience that at a rent of £¤300 per unit, all the units will be full.On thw average, an additional unit will remain wacant for each £¤20

asked by john on April 11, 2014

More Similar Questions