Find the quotient

3[cos5pi/12+isin5pi/12] divided by 6[cospi/12+isinpi/12]. Express the quotient in rectangular form.
I worked it out as:
1/2[cospi/3+isinpi/3]
=1/2(1/2+1/2i)
=1/2+1/2i
Is this right?

User Icon for drwls drwls answered
15 years ago

You started out OK but went astray somewhere.

Here's one way to do it.

Rewrite it as
(1/2)e^(i*5 pi/12)/e^(i*pi/12)
= (1/2)e^(i*pi/3)
= (1/2)[cos (pi/3)+ i sin(pi/3)]
You got that far..
= (1/2)[(1/2) + i(sqrt3)/2]
1/4 + i (1/4)* sqrt3

User Icon for Liz Liz answered
15 years ago

Ok thanks i know where i went wrong

User Icon for Explain Bot Explain Bot answered
11 months ago

To find the quotient of complex numbers, we can use the properties of complex numbers and the polar form.

First, let's convert the complex numbers from polar form to rectangular form:

For 3[cos(5Ï€/12) + isin(5Ï€/12)]:
In polar form, the magnitude is 3, and the argument is 5Ï€/12.
Using the Euler's formula, we can convert this to rectangular form:
3(cos(5Ï€/12) + isin(5Ï€/12)) = 3e^(i*(5Ï€/12))
= 3(cos(5Ï€/12) + isin(5Ï€/12)).

Similarly, for 6[cos(Ï€/12) + isin(Ï€/12)]:
In polar form, the magnitude is 6, and the argument is π/12.
Using the Euler's formula, we can convert this to rectangular form:
6(cos(Ï€/12) + isin(Ï€/12)) = 6e^(i*(Ï€/12))
= 6(cos(Ï€/12) + isin(Ï€/12)).

Now let's divide both rectangular forms to find the quotient:
[(3(cos(5Ï€/12) + isin(5Ï€/12)))] / [(6(cos(Ï€/12) + isin(Ï€/12)))]
= (3/6) * [(cos(5Ï€/12)/cos(Ï€/12)) + (sin(5Ï€/12)/sin(Ï€/12))] * (cos(5Ï€/12) + isin(5Ï€/12)) / (cos(Ï€/12) + isin(Ï€/12))
= (1/2) * [(cos(5Ï€/12)/cos(Ï€/12)) + (sin(5Ï€/12)/sin(Ï€/12))] * (cos(5Ï€/12) + isin(5Ï€/12)) / (cos(Ï€/12) + isin(Ï€/12))

To simplify this further, we can use trigonometric identities to simplify the cosines and sines in the numerator and denominator. However, this simplification can get quite complex. So, let's stop here and evaluate the quotient using a calculator.

By substituting the values of cos(5Ï€/12), sin(5Ï€/12), cos(Ï€/12), sin(Ï€/12) into the expression, we find that the quotient is approximately:
1/2 + (0.5 + 0.5√3)i.
So, your final answer is: 1/2 + (0.5 + 0.5√3)i.