Answer:
Step-by-step explanation:
given that certain tubes manufactured by a company have a mean lifetime of 800 hours and a standard deviation of 60 hours.
Sample size n =16
Std error of sample mean = 
x bar follows N(800, 15)
the probability that a random sample of 16 tubes taken from the group will have a mean lifetime
(a) between 790 and 810 hours,
=
(b) less than 785 hours
, (c) more than 820 hours,
(d) between 770 and 830 hours
=
We take each number as x = 2x 3x 4x
(2x)³+(3x)³+(4x)³=33957
8x³+27x³+64x³=33957
99x³=33957
x³=33957÷99
=∛343
x=7
2x=2×7=14
3x=3×7=21
4x=4×7=28
=the three numbers are 14,21,28
1/3 with a line over the answer ( 0.66666666666...)
The trig functions that you need to deal with are
Sine
Cosine
Tangent
Cotangent
Cosecant
Secant
You need to write a single expression using all six trig functions such that the value of the expression equals 3.
To make this as simple as possible, the first thing I would do is look up the values of these functions and identify which ones are equal to either 1/2 or 1.0 or 2.0
sin(30º) = 1/2
sin(90º) = 1
cos(0º) = 1
cos(60º) = 1/2
tan(45º) = 1
csc(30º) = 2
csc(90º) = 1
sec(0º) = 1
sec(60º) = 2
cot(45º) = 1
If we only had to use three trig functions (sin, cos, tan), one possibility is
tan(45º) + cos(0º)/sin(30º) = 1 + 1/(1/2) = 1 + 2 = 3
noticed how I chose one each of the required functions and the operations so that the result = 3.
Now it is up to you to figure out how to combine all six trig functions so that they equal zero. There are many possibilities for you to choose from..
