Given:
Triangle LJK.
LJ = 89 in, LK = 28 in and m∠L = 42°
To find:
The length of missing side JK.
Solution:
LJ = k = 89
LK = j = 28
JK = l = ?
Using law of cosine:
Substitute the given values.
Taking square root on both sides.
The length of the missing side is 70.7 in.
Answer:
The world population at the beginning of 2019 will be of 7.45 billion people.
Step-by-step explanation:
The world population can be modeled by the following equation.
In which Q(t) is the population in t years after 1980, in billions, Q(0) is the initial population and r is the growth rate.
The world population at the beginning of 1980 was 4.5 billion. Assuming that the population continued to grow at the rate of approximately 1.3%/year.
This means that
So
What will the world population be at the beginning of 2019 ?
2019 - 1980 = 39. So this is Q(39).
The world population at the beginning of 2019 will be of 7.45 billion people.