Answer:
0.969
Step-by-step explanation:
Given that:
Mean lifetime (m) = 520 hours
Variance = 900
Hence, standard deviation (s) = √900 = 30
Probability that bulb will last for at most 576 hours
X ≤ 576
Obtain the standardized score :
Using the relation :
Zscore = (x - m) / s
Zscore = (576 - 520) / 30
Zscore = 56 / 30
Zscore = 1.867
P(Z ≤ 1.867) : using the z probability calculator ;
P(Z ≤ 1.867) = 0.96905
Hence, P(Z ≤ 1.867) = 0.969
Hi there!

We are given:
cos(7x)cos(4x) = -1 - sin(7x)sin(4x)
Begin by moving all terms with variables to one side:
cos(7x)cos(4x) + sin(7x)sin(4x) = -1
The corresponding trig identity is cos(A - B). Thus:
cos(7x - 4x) = cos(7x)cos(4x) + sin(7x)sin(4x) = -1
cos(3x) = -1
cos = -1 at π, so:
3x = π
x = π/3
We can also find another solution. Let 3π = -1:
3x = 3π
x = π
Thus, solutions on [0, 2π) are π/3 and π.
Answer:
-4
Step-by-step explanation:
simplify both sides of the equation, subtract 4n from both sides, add 16 to both sides, divide both sides by -3
Answer:
The next term for the following sequence is 8/3