28! hope this helps, you just plug in 4 for x, and then multiply by two.
The answer is 125.6 because all you have to do is dived.
You can go full 2π rotate around counterclockwise so the angle wouldn't be negative.
So -π/2 + 2π = -π/2 + 4π/2 = 3π/2
So (4, 3π/2) is the same point as (4, -π/2)
Answer: Choice D. 
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Work Shown:
We multiply the coefficients 9.2 and 7 to get 64.4, which is the same as 6.44*10^1 in scientific notation. When multiplying exponential expressions with the same base, we add the exponents
This is what the steps could look like
The final result is in scientific notation as the coefficient c is restricted such that 
Answer: Hence Pair( x, y) = [ 105/2, 105/2]
Step-by-step explanation:
Given that;
Among all pairs of numbers with a sum of 105;
the pair whose product is maximum = ?
so let pairs of numbers with a sum of 105 be x and y respectively
x + y = 105
let y = 105 - x
now
product = xy = x( 105 - x ) = 105x - x²
now
p(x) = 105x - x²
for maximum value of p
dp/dx =0
⇒ dp/dx = 105 - 2x = 0
2x = 105
x = 105/2
y + x = 105
y = 105 - x
y = 105 - 105/2 = 105/2
Hence Pair( x, y) = [ 105/2, 105/2]
