Sunday

February 1, 2015

February 1, 2015

Posted by **Kate** on Friday, May 17, 2013 at 9:11am.

a) -5 + 5i

b) -5

c)-3 -4i

- TRIGONOMETRY -
**Steve**, Friday, May 17, 2013 at 9:51amthink back to your polar coordinates. Same thing.

(a+bi) = r cisθ

where

tanθ = y/x

r^2 = a^2 + b^2

-5+5i

r^2 = 5^2+5^2, so r=5√2

tanθ = -5/5 = -1

Now, cosθ=x/r sinθ=y/r

since x<0 and y>0, θ is in II, so

θ = 3π/4

-5 = -5+0i = 5 cis π

-3-4i = 5 cis π+arctan(-4/-3)

because we are in QIII

**Answer this Question**

**Related Questions**

TRIGONOMETRY - Can someone please give me a step by step answer on how to find ...

TRIGONOMETRY - I don't understand how to convert -3-4i to polar coordinates. I ...

Calculus--complex numbers - let z= a+bi be a complex number. it is given that ...

algebra - help me please im confused Consider the quadratic expression X^2 + 4x...

Physics - Can someone please show me step by step how to normalize e^-5x in the ...

complex numbers - how do you work out the the form a+ib when you are given the ...

Algebra 1--Step-by-Step - Can someone show me how to solve these step-by-step? ...

math - can someone show me how to simplify this complex fraction step by step. (...

stoichiometry problems - Hey I hve problems with calculate stoichiometry ...

trig - 6. Compute the modulus and argument of each complex number. I did a-c and...