12m
10m
9m
Answer:
The correct answer is: d=9m
Step-by-step explanation:
Ok, the ladders leaned against a building make two right triangles with same the same height, which we will call h. For the 20m ladder, its leg is (7+d) and for the 15m ladder, its leg is d, and the two hypotenuses are 20 and 15 respectively.
Then, using the Pythagorean Theorem we have:
20m ladder:
20^2 = h^2 + (d+7)^2 (Eq. 1)
400 = h^2 + d^2 + 2*7*d + 7^2 (expanding the theorem)
400 = (h^2 + d^2) + 14*d + 49 (Eq. 2)
15m ladder:
15^2 = h^2 + (d)^2 (Eq. 3)
Since h^2 + (d)^2 is equal to 15^2, we can substitute (2) into (3):
400 = (15^2) + 14*d + 49
400 = 225 + 14*d + 49
14*d = 400 - 225 - 49 (clearing the variable d)
14*d = 126
d = 9 m
And since we now know that d is equal to 9m. For the longer ladder is (d+7)=(9+7)=16m.
And, then the shorter ladder is 9m from the building and the longer ladder is 16m from the building
Answer:
Compared to the graph of y = x, the graph of y = -2x is steeper.
Compared to the graph of y = x, the graph of y = -2x intersects the y-axis at the same point.
Compared to the graph of y = x, the graph of y = x + ⅔ is equally steep.
Compared to the graph of y = x, the graph of y = x + ⅔ intersects the y-axis at a higher point.
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Answer:
see below
Step-by-step explanation:
a) The variance of random variable X is
−
33
4
−
4
33
.
b) The conditional PDF of Y given X is:
For
0
≤
�
≤
1
0≤y≤1,
�
(
�
∣
�
)
=
1
f(y∣x)=1.
For
�
y outside the range [0, 1],
�
(
�
∣
�
)
=
0
f(y∣x)=0.
Answer: y=5x+1
Step-by-step explanation: