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)]
Answer:
The small balloon bouquet uses 7 balloons and the large one uses
18 balloons.
Step-by-step explanation:
Let's say that small balloon bouquets are S and large balloon bouquets are L. For the graduation party the employee assembled 6 small bouquets and 6 large bouquets, the total number of balloon used is 150. To put the sentence into an equation will be:
6S + 6L= 150
S+L= 25 ----> 1st equation
For Father's Day, the employee uses 6 small bouquet and 1 large bouquet, the total number of balloons used is 60. The equation will be:
6S + 1L= 60
1L= 60- 6S ----> 2nd equation
We can solve the number of small balloon bouquet by substitute the 2nd equation into 1st. The calculation will be:
S+L = 25
S+ (60-6S)= 25
-5S= 25-60
-5S= -35
S= -35/-5
S=7
Then we can find L by substitute S value to 1st or 2nd equation.
S+L=25
7+L=25
L=18
Hope this helps ;)
Answer:
47 weeks
Step-by-step explanation:
you multiply 20 times 5 because he makes 5 dollars and hour and works 20 hours a week, so then you get 100. so he makes 100 dollars in a week. then you divide 100 by 4650 and get 46.5 which rounded up is 47. so he needs to work 47 weeks.
1 = 90
2 = 65
3 = 65
4 = 25
90+25=115
180-115=65
have a merry christmas :)
