A or 5/7, they’re both odd numbers so it cannot be simplified any further
-5x + 2 > -38
-5x > -40
x < 8
-5x + 2 < -8
-5x < -10
x > 2
so the inequality becomes
2 < x < 8
so the graph will be a straight line with open circles on 2 and 8 and shading in between these values.
Surface area of the cylinder = 816.4 sq. ft.
Solution:
Height of the cylinder = 21 ft
Diameter of the cylinder = 10 ft
Radius of the cylinder = 10 ÷ 2 = 5 ft
Use the value of
= 3.14
Surface area of the cylinder = 
Substitute the given values in the surface area formula, we get
Surface area of the cylinder 

ft²
Hence the surface area of the cylinder is 816.4 sq. ft.
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, ∞)