Answer:
49 - x^2
Step-by-step explanation:
(7+x)(7-x)
We know this is the difference of squares
(a-b) (a+b) = a^2 - b^2
7^2 - x^2 = 49-x^2
We can also FOIL
first = 7*7 = 49
Outer: = 7x
Inner: = -7x
Last : -x*x = -x^2
Add them together
49 +7x-7x - x^2
Combine like terms
49-x^2
Answer:
a. E(x) = 3.730
b. c = 3.8475
c. 0.4308
Step-by-step explanation:
a.
Given
0 x < 3
F(x) = (x-3)/1.13, 3 < x < 4.13
1 x > 4.13
Calculating E(x)
First, we'll calculate the pdf, f(x).
f(x) is the derivative of F(x)
So, if F(x) = (x-3)/1.13
f(x) = F'(x) = 1/1.13, 3 < x < 4.13
E(x) is the integral of xf(x)
xf(x) = x * 1/1.3 = x/1.3
Integrating x/1.3
E(x) = x²/(2*1.13)
E(x) = x²/2.26 , 3 < x < 4.13
E(x) = (4.13²-3²)/2.16
E(x) = 3.730046296296296
E(x) = 3.730 (approximated)
b.
What is the value c such that P(X < c) = 0.75
First, we'll solve F(c)
F(c) = P(x<c)
F(c) = (c-3)/1.13= 0.75
c - 3 = 1.13 * 0.75
c - 3 = 0.8475
c = 3 + 0.8475
c = 3.8475
c.
What is the probability that X falls within 0.28 minutes of its mean?
Here we'll solve for
P(3.73 - 0.28 < X < 3.73 + 0.28)
= F(3.73 + 0.28) - F(3.73 + 0.28)
= 2*0.28/1.3 = 0.430769
= 0.4308 -- Approximated
8505. You would do 63 times 135 to get 8505
A pair of the opposite sides of a hexagon has equal length and this is proved below.
<h3>How to illustrate the hexagon?</h3>
It should be noted that a hexagon is a polygon that has six sides.
In this case, it has 6 sides.
The total angles will be:
= (n - 2) × 180
= (6 - 2) × 180
= 720°
Each angle will hence be:
= 720°/6
= 120°
Each angle are equal and this illustrates that the parallel sides are equal.
A diagram is attached to illustrate the pair of parallel sides.
Learn more about hexagon on:
brainly.com/question/1615720
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