Answer:
C)
Step-by-step explanation:
By the cos double angle formula, we know Substituting into the formula, we get
.
The answer is C.
The heat produced by current I is
H = I²R
where
R = resistance.
According to the formula, heat produced is proportional to the square of the current.
When a current of I = 2 amps is applied, the heat produced is
H = 10x³ + 80.
This heat includes heat due to a fixed current of 2 amps, and heat due to a variable current of x amps.
Because the heat produced is proportional to the square of the current, write the expressions as
H = (10x)*(x²) + 20*(2²)
The second term on the right is heat due to the fixed current of 2 amps, written as
20*(2²).
Therefore the fixed resistance is R = 20 ohms, and the square of the fixed current is 2².
The first term represents heat due to variable resistance, written as
(10x)*(x²).
Therefore the variable resistance is 10x, and the square of the variable current is x².
Answer:
The variable current is 10x.
The axis of symmetry is 2 and the vertex is (2, 4).
Answer:
$6.4
Step-by-step explanation:
You just do 32 × .2 to give you the discount of 6.4
You multiple by .2 because 20% as a decimal is .2 ( you do 20% divided by 100 to give you .2)