Answer:
-8i
Step-by-step explanation:
To multiply numbers is polar form
z1 = r1 ( cos theta 1 + i sin theta 1)
z2 = r2 ( cos theta 2 + i sin theta 2)
z1*z2 = r1*r2 (cos (theta1+theta2) + i sin (theta1+theta2)
z1 = 2(cos 70° + i sin 70°)
z2 = 4(cos 200+ i sin 200)
z1z2 = 2*4 (cos (70+200) + i sin (70+200)
z1z2 = 8 (cos(270) + i sin (270))
= 8 (0 + i (-1))
=-8i
Answer:
idrk tbh
Step-by-step explanation:
sorry for not being any help ;))
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Answer:
6.28 gallons
Step-by-step explanation:
first we need to find the area of a half sphere, and then find how much paint will be needed for that area.
The area of a sphere:

thus, the area of half a sphere is:

we know that the radius is:

we substitute this to find the area of the half sphere (the area they need to paint):

now the question is how many gallons of paint are needed to paint 2,513.27 square feet.
We are told that 1 gallon covers 400 square feet
thus, we must divide 2,513.27 by 400:

6.28 gallons of paint are needed.