Note that f(x) as given is <em>not</em> invertible. By definition of inverse function,
which is a cubic polynomial in 
with three distinct roots, so we could have three possible inverses, each valid over a subset of the domain of f(x).
Choose one of these inverses by restricting the domain of f(x) accordingly. Since a polynomial is monotonic between its extrema, we can determine where f(x) has its critical/turning points, then split the real line at these points.
f'(x) = 3x² - 1 = 0 ⇒ x = ±1/√3
So, we have three subsets over which f(x) can be considered invertible.
• (-∞, -1/√3)
• (-1/√3, 1/√3)
• (1/√3, ∞)
By the inverse function theorem,
where f(a) = b.
Solve f(x) = 2 for x :
x³ - x + 2 = 2
x³ - x = 0
x (x² - 1) = 0
x (x - 1) (x + 1) = 0
x = 0 or x = 1 or x = -1
Then 
can be one of
• 1/f'(-1) = 1/2, if we restrict to (-∞, -1/√3);
• 1/f'(0) = -1, if we restrict to (-1/√3, 1/√3); or
• 1/f'(1) = 1/2, if we restrict to (1/√3, ∞)
(4x - 4) - 3 simplified = 4x -7
Answer:
x = cost of each gift basket = $14.5
y = one time delivery fee = $135
Step-by-step explanation:
Let
x = cost of each gift basket
y = one time delivery fee
40x + y = 715 (1)
400x + y = 5935 (2)
Subtract (1) from (2)
400x - 40x = 5935 - 715
360x = 5220
x = 5220/360
x = 14.5
Substitute x = 14.5 into (1)
40x + y = 715 (1)
40(14.5) + y = 715
580 + y = 715
y = 715 - 580
y = 135
x = cost of each gift basket = $14.5
y = one time delivery fee = $135
Answer: 15.59 or 9√3
Step-by-step explanation:
We can use the Pythagorean Theorem to calculate the third side.
c² = a² + b² In a 30 60 90 Triangle, the hypotenuse is twice the length of the short leg of the right angle.
c is the hypotenuse. a is the short leg
18² = 9² + b²
324 = 81 + b² Subtract 81 from both sides.
324 - 81 = b² becomes b² = 243 Take the square root of both sides
b = 15.5884 . This can be rounded to 15.59 or 15.6 depending on significant digits or amount of precision required.
The proportions of the sides of the 30 60 90 triangle can also be used:
2² = 1² + b²
4 = 1 + b²
3 = b²
√3 = b
You can always multiply the length of the short leg by √3 to get the length of the side opposite the 60° angle
