write 2=5cis 11pie/6 in standard form.

Your question makes no sense to me as written but

2 = 5 cos 11 pi/6 + 5 i sin 11 pi/6
= 5 e^i(11 pi/6)
12 pi/6 = 2 pi is a full circle
11 pi/6 is a full circle - pi/6
2/5 = cos (12 pi/6 -pi/6) + i sin(12 pi/6 - pi/6)

2/5 = cos (-pi/6) + i sin (-pi/6)
2/5 = +sqrt (3)/2 - i/2

I'm not sure if the answer's a) 5sqrt3/2-5/2i b) 5sqrt3/2+5/2i c) -5sqrt3/2-5/2i d) -5sqrt3/2+5/2i

check for typo why do you have 2 on the left

if you had x and not 2 on the left it would be a

Okay thanks so much! that's right

To convert a complex number from polar form to standard form, we can use the formula:

a + bi = r(cosθ + isinθ)

where a + bi is the standard form of the complex number, r is the magnitude or modulus of the complex number, θ is the argument or angle of the complex number.

In the given complex number, 2 = 5cis(11π/6), we have:
- The magnitude, r = 5,
- The argument, θ = 11π/6.

To convert it to standard form, we substitute these values into the formula:

2 = 5(cos(11π/6) + isin(11π/6))

Now, let's evaluate the trigonometric functions for the given angle:

cos(11π/6) = cos(π + π/6) = -cos(π/6) = -√3/2
sin(11π/6) = sin(π + π/6) = -sin(π/6) = -1/2

Substituting these values back into the formula:

2 = 5*(-√3/2 + (-1/2)i)

Now, let's simplify:

2 = -5√3/2 - 5/2 i

Finally, we multiply every term in the expression by 2 to eliminate the denominator:

4 = -5√3 - 5i

Therefore, the complex number 2 = 5cis(11π/6) in standard form is 4 = -5√3 - 5i.