Solve for x:
x^9 = n x
Subtract n x from both sides:
x^9 - n x = 0
Factor x and constant terms from the left hand side:
-x (n - x^8) = 0
Multiply both sides by -1:
x (n - x^8) = 0
Split into two equations:
x = 0 or n - x^8 = 0
Subtract n from both sides:
x = 0 or -x^8 = -n
Multiply both sides by -1:
x = 0 or x^8 = n
Taking 8^th roots gives n^(1/8) times the 8^th roots of unity:
Answer: x = 0 or x = -n^(1/8) or x = -i n^(1/8) or x = i n^(1/8) or x = n^(1/8) or x = -(-1)^(1/4) n^(1/8) or x = (-1)^(1/4) n^(1/8) or x = -(-1)^(3/4) n^(1/8) or x = (-1)^(3/4) n^(1/8)
The correct answer for the question that is being presented above is this one: "<span>C) </span>4.2 inches." Bella has sampled the heights of 30 students at Ridgemont High and obtained a mean of 64.2 inches. He constructs a 90% confidence interval, which turns out to be (61.0, 67.4). The margin of error is <span>C) </span><span>4.2 inches </span>
Answer:
It's change of subject. :)
Given:
The power generated by an electrical circuit (in watts) as function of its current x (in amperes) is modeled by:
To find:
The current that will produce the maximum power.
Solution:
We have,
Here, leading coefficient is negative. So, it is a downward parabola.
Vertex of a downward parabola is the point of maxima.
If a parabola is 
, then
In the given function, a=-12 and b=120. So,
Putting x=5 in the given function, we get
Therefore, 5 watt current will produce the maximum power of 300 amperes.
