I need help on. This pls
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Answer:
The answer to your question is 90 dB
Step-by-step explanation:
Data
I = 10⁻³
I⁰ = 10⁻¹²
Formula
Loudness = 10log ()
Process
1.- To solve this problem, just substitute the values in the equation and do the operations.
2.- Substitution
Loudness = 10 log
3.- Simplify
Loudness = 10log (1 x 10⁹)
Loudness = 10(9)
Loudness = 90
Givens
y = 2
x = 1
z(the hypotenuse) = √(2^2 + 1^2) = √5
Cos(u) = x value / hypotenuse = 1/√5
Sin(u) = y value / hypotenuse = 2/√5
Solve for sin2u
Sin(2u) = 2*sin(u)*cos(u)
Sin(2u) = 2() = 4/5
Solve for cos(2u)
cos(2u) = - sqrt(1 - sin^2(2u))
Cos(2u) = - sqrt(1 - (4/5)^2 )
Cos(2u) = -sqrt(1 - 16/25)
cos(2u) = -sqrt(9/25)
cos(2u) = -3/5
Solve for Tan(2u)
tan(2u) = sin(2u) / cos(2u) = 4/5// - 3/5 = - 0.8/0.6 = - 1.3333 = - 4/3
Notes
One: Notice that you would normally rationalize the denominator, but you don't have to in this case. The formulas are such that they perform the rationalizations themselves.
Two: Notice the sign on the cos(2u). The sin is plus even though the angle (2u) is in the second quadrant. The cos is different. It is about 126 degrees which would make it a negative root (9/25)
Three: If you are uncomfortable with the tan, you could do fractions.
Multiply the first equation by 3 and the second equation by 2:
Subtract the two equation to get rid of the x variable:
Use the value of y to determine the value of x: for example, using the first equation we have