First subtract 2 revolutions from the - 840 :- (- (840-720) = -120
This gives sin -120 which is in the 3rd quadrant of the unit circle
sin -120 = - sin 60 = - sqrt3/2
Answer:
1661.06 cm²
Step-by-step explanation:
From the question given above, the following data were obtained:
Radius (r) = 11.5 cm
Size of synthetic leather needed =?
To know how many square centimetres of synthetic leather needed to cover the ball, we shall determine the area of the ball. This can be obtained as follow:
Radius (r) = 11.5 cm
Pi (π) = 3.14
Area of ball =?
The shape of a ball is spherical in nature. Thus, we shall apply the formula for calculating the area of a sphere. This is illustrated below:
A = 4πr²
A = 4 × 3.14 × 11.5²
A = 4× 3.14 × 132.25
A = 1661.06 cm²
Thus, 1661.06 cm² of synthetic leather needed to cover the ball.
The equation to show the depreciation at the end of x years is

Data;
- cost of machine = 1500
- annual depreciation value = x
<h3>Linear Equation</h3>
This is an equation written to represent a word problem into mathematical statement and this is easier to solve.
To write a linear depreciation model for this machine would be
For number of years, the cost of the machine would become

This is properly written as

where x represents the number of years.
For example, after 5 years, the value of the machine would become

The value of the machine would be $500 at the end of the fifth year.
From the above, the equation to show the depreciation at the end of x years is f(x) = 1500 - 200x
Learn more on linear equations here;
brainly.com/question/4074386
Since the equation says "cos(x-2)", we know that the horizontal displacement is 2 units.