Question 21
Let's complete the square
y = 3x^2 + 6x + 5
y-5 = 3x^2 + 6x
y - 5 = 3(x^2 + 2x)
y - 5 = 3(x^2 + 2x + 1 - 1)
y - 5 = 3(x^2+2x+1) - 3
y - 5 = 3(x+1)^2 - 3
y = 3(x+1)^2 - 3 + 5
y = 3(x+1)^2 + 2
Answer: Choice D
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Question 22
Through trial and error you should find that choice D is the answer
Basically you plug in each of the given answer choices and see which results in a true statement.
For instance, with choice A we have
y < -4(x+1)^2 - 3
-7 < -4(0+1)^2 - 3
-7 < -7
which is false, so we eliminate choice A
Choice D is the answer because
y < -4(x+1)^2 - 3
-9 < -4(-2+1)^2 - 3
-9 < -7
which is true since -9 is to the left of -7 on the number line.
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Question 25
Answer: Choice B
Explanation:
The quantity (x-4)^2 is always positive regardless of what you pick for x. This is because we are squaring the (x-4). Squaring a negative leads to a positive. Eg: (-4)^2 = 16
Adding on a positive to (x-4)^2 makes the result even more positive. Therefore (x-4)^2 + 1 > 0 is true for any real number x.
Visually this means all solutions of y > (x-4)^2 + 1 reside in quadrants 1 and 2, which are above the x axis.
A cross section is the two dimensional shape that is created when a slice is made through a solid figure by an intersection of a plane and the solid body.
A square pyramid is a pyramid with a square base.
Case 1: When the plane intersects the square pyramid at an angle perpendicular to the base but not through the vertex. In this case a trapezoid is formed.
Case 2: When the plane intersects the square pyramid at an angle perpendicular to the base and through the vertex. In this case a triangle is formed.
Case 3: When the plane intersects the square pyramid at an angle parallel to the base. In this case a square is formed.
<span>Therefore, a
cross section made by the intersection of a plane and a square
pyramid at an angle either parallel or perpendicular to the base can be of shapes:
-square
-triangle
-trapezoid</span>
Answer:
8.33
Step-by-step explanation:
D because it is a decimal (lower than 0)
6......................................... i mean this is probably wrong but yeah
