Find the principal value of the following expressions. Write your answer in the form a + ib.

(a)

(b)

(c)

  (a) -0.266255 -0.963903i

  (b) -1.381098

  (c) -2.156385 +0.273077i

Step-by-step explanation:

A suitable calculator is very handy for such questions. See attached.

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Euler's relation and the definitions of sin and cosh in exponential terms are helpful.

(a)

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(b)

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(c)

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The useful relations are ...

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18