Answer:
True.
Step-by-step explanation:
Given,
4cos2 (4x) - 3 = 0
Now, 4π/24 = π/6
Or, cos π/6 = √3/2
Or, cos^2 π/6 = 3/4
Or, 4 cos^2 π/6 = 3
Now, Left Hand Side= 4cos2 (4x) - 3
= 3-3 =0 = Right Hand Side (Proved)
Here, Left Hand Side= Right Hanad Side. So, 4cos2 (4x) - 3=0 is true.
Answer:
Step-by-step explanation:
In the past, mean of age of employees
i.e. 
Recently sample was taken
n = sample size = 60
Mean of sample = 45
Std dev of sample s = 16

(Right tailed test)
Since only population std deviation is known we can use t test only
Std error = 
Mean difference = 45-40 =5
Test statistic t=
df = 60
p value =0.008739
Since p < 0.05 we reject null hypothesis
The mean age has increased.
The answer to c. Is 8t+12g