Answer:
see explanation
Step-by-step explanation:
I don't have graphing facilities but can give you the vertex and 1 other point.
Given a parabola in standard form
y = ax² + bx + c ( a ≠ 0 )
Then the x- coordinate of the vertex is
x = - 
y = - x² - 2x + 8 ← is in standard form
with a = - 1 and b = - 2 , then
x = - 
= - 1
Substitute x = - 1 into the equation for corresponding value of y
y = - (- 1)² - 2(- 1) + 8 = - 1 + 2 + 8 = 9
vertex = (- 1, 9 )
To obtain another point substitute any value for x into the equation
x = 0 : y = 0 - 0 + 8 , then (0, 8 ) is a point on the graph
x = 2 : y = - (2)² - 2(2) + 8 = - 4 - 4 + 8 = 0 then (2, 0 ) is a point on the graph
Given:
A circle of radius r inscribed in a square.
To find:
The expression for the area of the shaded region.
Solution:
Area of a circle is:
Where, r is the radius of the circle.
Area of a square is:
Where, a is the side of the square.
A circle of radius r inscribed in a square. So, diameter of the circle is equal to the side of the square.
So, the area of the square is:
Now, the area of the shaded region is the difference between the area of the square and the area of the circle.
Therefore, the correct option is (a).
Step-by-step explanation:
You can find the area of a right triangle the same as you would any other triangle by using the following formula:
A = (1/2)bh, where A is the area of the triangle, b is the length of the base and h is the height of the triangle; However, with a right triangle, it's much more convenient in finding its area if we utilize the lengths of the two legs (the two sides that are shorter than the longest side, the hypotenuse and that are perpendicular to each other and thus form the right angle of the right triangle), that is, since the two legs of a right triangle are perpendicular to each other, when we treat one leg as the base, then, consequently, we can automatically treat the length of the other leg as the height, and if we initially know the lengths of both legs, then we can then just plug this information directly into the area formula for a triangle to find the area A of the right triangle.
For example: Find the area of a right triangle whose legs have lengths of 3 in. and 4 in.
Make the 4 in. leg the base. Since the two legs of a right triangle are perpendicular to each other, then the length of the other leg is automatically the height of the triangle; therefore, plugging this information into the formula for the area of a triangle, we have:
A = (1/2)bh
= (1/2)(4 in.)(3 in.)
= (1/2)(12 in.²)
A = 6 in.² (note: in.² means square inches)
