Answer:
x = π/2 + πk
Step-by-step explanation:
cot² x csc² x + 2 csc² x − cot² x = 2
Multiply both sides by sin² x:
cot² x + 2 − cos² x = 2 sin² x
Add cos² x to both sides:
cot² x + 2 = 2 sin² x + cos² x
Pythagorean identity:
cot² x + 2 = sin² x + 1
Subtract 1 from both sides:
cot² x + 1 = sin² x
Pythagorean identity:
csc² x = sin² x
Multiply both sides by sin² x:
1 = sin⁴ x
Take the fourth root:
sin x = ±1
Solve for x:
x = π/2 + 2πk, 3π/2 + 2πk
Which simplifies to:
x = π/2 + πk
Answer:
x = -5
Step-by-step explanation:
Since these two triangles are similar, the ratio between the corresponding lengths of each triangle will be the same.
This means the ratio between one side of each triangle (e.g. AD and DC) will be the same as the ratio between a different side of each triangle (e.g. BE and BC).
So, to create an equation for the sides which contain the unknown 'x', we must first find the ratio between the two sides by using a different set of sides.
On the right side we are given 9 for AD, and 18 for DC.
9/18 = 0.5
This means that the extra length of the larger triangle from the smaller one (AD) is half the length of the smaller triangle (DC). We can use this to make an equation for x:
If AD/DC = 0.5, then BE/EC will also = 0.5
BE = x+23
EC = x+41
Therefore:
Now we can solve by multiplying both sides by x+41 to eliminate the fraction:
Now we multiply out the brackets and move the terms to different sides:
And if we substitute the -5 into the equations:
-5+23 = 18
-5 + 41 = 36
We will see that -5 does indeed give us the same ratio between the lengths:
18/36 = 0.5
Hope this helped!
The data distribution is positively skewed
Answer:
21+j=55
Step-by-step explanation:
It says sum, which means to add(+). So you add 21 and j (21+j) and that equals 55 (=55). Then you add all the pieces together and you get 21+j=55
Answer:
1222 billion dollars.
Step-by-step explanation:
To find the total increase from 1960 to 2010, we need to find the growth of each decade and sum them all:
In the period 1960-1970, we have x = 1, and the growth is:
In the period 1970-1980, we have x = 2, and the growth is:
The growth in the following 3 periods are:
So the total growth in the period 1960 - 2010 is:
Rounding to the nearest billion dollars, we have a total of 1222 billion dollars.