<span>7x/9x = 7/9
hope it helps</span>
Answer: 18
Step-by-step explanation:
The formula to find the minimum sample size is given by :_
, where 
= population standard deviation.
z*= critical z-value.
E= Margin of error.
Given : 
E= ± 8
We know that critical value corresponding to 99% confidence level = z*=2.576 [Using z-table]
Then, the required sample size would be :
[Round to next integer.]
Hence, the required minimum sample size = 18
Answer:
x = -1, y = 7
Step-by-step explanation:
8x + 3y = 13
3x + 2y = 11
Multiply the first equation by -2 and the second equation by 3. Then add them.
-16x - 6y = -26
(+) 9x + 6y = 33
--------------------------
-7x = 7
x = -1
Now substitute x = -1 in the first original equation and solve for y.
8x + 3y = 13
8(-1) + 3y = 13
-8 + 3y = 13
3y = 21
y = 7
Answer: x = -1, y = 7
The period of y = 4 cos(8πx) is 2π/(8π) = 1/4, since
cos(x - 2π) = cos(x)
and if we replace x with 8πx, we get
cos(8πx - 2π) = cos(8πx)
and
8πx - 2π = 8π (x - 1/4)
Answer:
if f(x) = ax + b then f-1(x) = (x - b)/a
Step-by-step explanation:
Now
f(x)=ax + b
then y = ax + b
interchanging x and y , we get
or, x = ay + b
or, x - b = ay
or, (x - b)/a = y
therefore,f-1(x) = (x - b)/a
