Answer: < -8.1961, 6.7189 >
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Explanation:
Vector u has magnitude 8 and direction 150 degrees.
So r = 8 and theta = 150
The polar form
r*(cos(theta)+i*sin(theta))
updates to
8*(cos(150)+i*sin(150))
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Use your calculator to evaluate that last expression to get it into a+bi form
8*(cos(150)+i*sin(150))
8*(-0.866025 + i*0.5)
-6.9282 + 4i
So this is the a+bi form of vector u. It's a rough approximation of it.
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Repeat those steps for vector v
v = r*(cos(theta)+i*sin(theta))
v = 3*(cos(115)+i*sin(115))
v = 3*(-0.422618 + i*0.906308)
v = -1.267854 + 2.718924i
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We're converting each vector to a+bi form so that we can add the vectors.
The general idea is that if you want to add v = a+bi and w = c+di, then
v+w = (a+c)+(b+d)i
we simply add the corresponding real components together, and the imaginary components are added together as well.
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Add up u and v
u+v = (-6.9282 + 4i) + (-1.267854 + 2.718924i)
u+v = (-6.9282 + -1.267854) + (4i + 2.718924i)
u+v = -8.196054 + 6.718924i
When rounding to four decimal places, the real and imaginary components are -8.1961 and 6.7189 respectively. These represent the x and y components of the vector.
So we can say vector u+v is approximately < -8.1961, 6.7189 >
