Question 1:
(a) Using sine rule
ground/Sin 49 = plank/Sin 90
But sine 90 = 1, ground = 3 ft
Then,
3/Sin 49 = plank
Length of the plank = 3/Sin 49 ≈ 4.0 ft (rounded to nearest tenth)
(b) Height where the plank touches the wall
wall = Sqrt (plank^2 - ground^2) = Sqrt (4.0^2 - 3.0^2) ≈ 2.6 ft (Rounded to nearest tenth)
Question 2:
(a) Angle x
ground = 24 ft
support wire = 30 ft
Applying sine rule
support wire/Sin 90 = ground/Sin (90-x) ----- but Sin 90 = 1
Then,
Support wire = ground/Sin (90-x)
Sin (90-x) = ground/support wire = 24/30 = 0.8
90-x = Sin^-1(0.8) = 53.13 => x = 90-53.13 = 36.9°
(b) Height where the wire touches the tree (tree)
tree = Sqrt (support wire^2 - ground^2) = Sqrt (30^2 - 24^2) = 18 ft
by angle sum property in traingle having ,
$50+70+x=180 \implies x=60^{\circ}$
now, by exterior angle property of triangle, $x+y=60+50$
put $x=60$ to get $y=50$
Answer:
plus or minus √10 / 4
Step-by-step explanation:
0=-16t^2 +10 becomes easier to solve if we rewrite it as 16t^2 = 10.
Then t^2 = 10/16 = 5/8, and t = plus or minus √(5/8), or
t = plus or minus (√5) / √8), or
t = plus or minus (√5)√8 √5*2√2
------------- = -------------------
8 8
or plus or minus √10 / 4
Answer:
13
Step-by-step explanation:
5 12 and 13 are a known triangle proportion relation.
also, 5 squared plus 12 squared is 169.
13 squared is 169.
(I just used the Pythagorean formula)
The expected number of female children in a family with three children is 1.5.
The correct option is B.
We have to determine
What is the expected number of female children in a family with three children?
<h3>Probability;</h3>
Probability is defined as the sum of all observations and the number of observations.
The expected value of female children= Probability of female children x Total number of children.
A child can be male or female, so there are 2 combinations, the favorable outcome is female.
The probability of female children = 1/2.
Therefore,
The expected number of female children in a family with three children is;
Hence, The expected number of female children in a family with three children is 1.5.
To know more about probability click the link given below.
brainly.com/question/743546