Answer:
option (a) It will be closer to 30 than to 20
Step-by-step explanation:
Data provided in the question:
For sample 1:
n₁ = 10
variance, s₁² = 20
For sample 2:
n₂ = 15
variance, s₂² = 30
Now,
The pooled variance is calculated using the formula,

on substituting the given respective values, we get

or
= 26.0869
Hence,
the pooled variance will be closer to 30 than to 20
Therefore,
The correct answer is option (a) It will be closer to 30 than to 20
Answer:
The graph of y = f(-x) is a reflection of the graph of y = f(x) in the x-axis. ⇒ False
The graph of y = -f(x) is a reflection of the graph of y = f(x) in the y-axis. ⇒ False
Step-by-step explanation:
<em>Let us explain the reflection about the axes</em>
- If a graph is reflected about the x-axis, then the y-coordinates of all points on it will opposite in sign
Ex: if a point (2, -3) is on the graph of f(x), and f(x) is reflected about the x-axis, then the point will change to (2, 3)
- That means reflection about the x-axis change the sign of y
- y = f(x) → reflection about x-axis → y = -f(x)
- If a graph is reflected about the y-axis, then the x-coordinates of all points on it will opposite in sign
Ex: if a point (-2, -5) is on the graph of f(x), and f(x) is reflected about the y-axis, then the point will change to (2, -5)
- That means reflection about the y-axis change the sign of x
- y = f(x) → reflection about y-axis → y = f(-x)
<em>Now let us answer our question</em>
The graph of y = f(-x) is a reflection of the graph of y = f(x) in the x-axis.
It is False because reflection about x-axis change sign of y
The graph of y = -f(x) is a reflection of the graph of y = f(x) in the x-axis
The graph of y = -f(x) is a reflection of the graph of y = f(x) in the y-axis.
It is False because reflection about y-axis change sign of x
The graph of y = f(-x) is a reflection of the graph of y = f(x) in the y-axis
Answer:C
Step-by-step explanation:
<span> 3x^2 − 6x = 24
</span>3x^2 − 6x - 24 = 0
3(x^2 - 2x - 8) = 0
3(x - 4)(x + 2) = 0
x - 4 = 0; x = 4
x + 2 =0; x = -2
answer
<span>C) x = −2, x = 4</span>