Answer:
a. cosθ = ¹/₂[e^jθ + e^(-jθ)] b. sinθ = ¹/₂[e^jθ - e^(-jθ)]
Step-by-step explanation:
a.We know that
e^jθ = cosθ + jsinθ and
e^(-jθ) = cosθ - jsinθ
Adding both equations, we have
e^jθ = cosθ + jsinθ
+
e^(-jθ) = cosθ - jsinθ
e^jθ + e^(-jθ) = cosθ + cosθ + jsinθ - jsinθ
Simplifying, we have
e^jθ + e^(-jθ) = 2cosθ
dividing through by 2 we have
cosθ = ¹/₂[e^jθ + e^(-jθ)]
b. We know that
e^jθ = cosθ + jsinθ and
e^(-jθ) = cosθ - jsinθ
Subtracting both equations, we have
e^jθ = cosθ + jsinθ
-
e^(-jθ) = cosθ - jsinθ
e^jθ + e^(-jθ) = cosθ - cosθ + jsinθ - (-jsinθ)
Simplifying, we have
e^jθ - e^(-jθ) = 2jsinθ
dividing through by 2 we have
sinθ = ¹/₂[e^jθ - e^(-jθ)]
Let julia's age be x
Let Kara's age be 4x
x+4x=13
5x=13
x=13/5
2.6 years
The equation that is equivalent to S=pi r^2 h is h = S/pir^2
<h3>Subject of formula</h3>
This is a way of representing a variable with another. Given the equation
S=pi r^2 h
We are to make 'h" the subject of the formula.
Divide both sides by pir^2
S/pir^2 =pi r^2 h/pir^2
h = S/pir^2
Hence the equation that is equivalent to S=pi r^2 h is h = S/pir^2
Learn more on subject of formula here: brainly.com/question/657646
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1.04 ^ 1/12 = 0.086666666
or
1.04 ^ 1/12 = 13/150
Answer:
Step-by-step explanation:
Hope this helps!
