Basically 3 : horizontally, diagonally, and vertically.
The <em>correct answer</em> is:
Her number is 7.
Explanation:
Let x represent her number.
She triples her number; this is represented by 3x.
She then adds 5 to this; this gives us 3x+5.
She gets 26 aas her answer. This gives us the equation:
3x+5 = 26
To solve this, first subtract 5 from each side:
3x+5-5 = 26-5
3x = 21
Divide each side by 3:
3x/3 = 21/3
x = 7
<span>Maximum area = sqrt(3)/8
Let's first express the width of the triangle as a function of it's height.
If you draw an equilateral triangle, then a rectangle using one of the triangles edges as the base, you'll see that there's 4 regions created. They are the rectangle, a smaller equilateral triangle above the rectangle, and 2 right triangles with one leg being the height of the rectangle and the other 2 angles being 30 and 60 degrees. Let's call the short leg of that triangle b. And that makes the width of the rectangle equal to 1 minus twice b. So we have
w = 1 - 2b
b = h/sqrt(3)
So
w = 1 - 2*h/sqrt(3)
The area of the rectangle is
A = hw
A = h(1 - 2*h/sqrt(3))
A = h*1 - h*2*h/sqrt(3)
A = h - 2h^2/sqrt(3)
We now have a quadratic equation where A = -2/sqrt(3), b = 1, and c=0.
We can solve the problem by using a bit of calculus and calculating the first derivative, then solving for 0. But since this is a simple quadratic, we could also take advantage that a parabola is symmetrical and that the maximum value will be the midpoint between it's roots. So let's use the quadratic formula and solve it that way. The 2 roots are 0, and 1.5/sqrt(3).
The midpoint is
(0 + 1.5/sqrt(3))/2 = 1.5/sqrt(3) / 2 = 0.75/sqrt(3)
So the desired height is 0.75/sqrt(3).
Now let's calculate the width:
w = 1 - 2*h/sqrt(3)
w = 1 - 2* 0.75/sqrt(3) /sqrt(3)
w = 1 - 2* 0.75/3
w = 1 - 1.5/3
w = 1 - 0.5
w = 0.5
The area is
A = hw
A = 0.75/sqrt(3) * 0.5
A = 0.375/sqrt(3)
Now as I said earlier, we could use the first derivative. Let's do that as well and see what happens.
A = h - 2h^2/sqrt(3)
A' = 1h^0 - 4h/sqrt(3)
A' = 1 - 4h/sqrt(3)
Now solve for 0.
A' = 1 - 4h/sqrt(3)
0 = 1 - 4h/sqrt(3)
4h/sqrt(3) = 1
4h = sqrt(3)
h = sqrt(3)/4
w = 1 - 2*(sqrt(3)/4)/sqrt(3)
w = 1 - 2/4
w = 1 -1/2
w = 1/2
A = wh
A = 1/2 * sqrt(3)/4
A = sqrt(3)/8
And the other method got us 0.375/sqrt(3). Are they the same? Let's see.
0.375/sqrt(3)
Multiply top and bottom by sqrt(3)
0.375*sqrt(3)/3
Multiply top and bottom by 8
3*sqrt(3)/24
Divide top and bottom by 3
sqrt(3)/8
Yep, they're the same.
And since sqrt(3)/8 looks so much nicer than 0.375/sqrt(3), let's use that as the answer.</span>
We have been given three statements. From those statements, we have to pick the statement that can conclude that that two lines are parallel.
Statement 1:
If right angles are formed, then lines are parallel.
This is not valid because if the angle formed is right angle then lines forming right angle will be perpendicular.
Statement 2:
If two lines are perpendicular to another line, then they are parallel.
This is valid because the line on which other two lines are perpendicular will work as transversal and the alternet interior angles will be equal. Hence the two perpendicular lines on given line will be parallel to each other.
Statement 3:
If alternate interior angles are equal, then lines are parallel.
This is valid as explained above.
Hence final answer are statement 2 and statement 3 both.
Answer:
John is currently 6 years old.
Step-by-step explanation:
2 years ago: x years
Current time: x+2
In 6 years: x+8
EQUATION:
3(x)=x+8= 3x=x+8
(subract x from both sides)
2x=8
x=4
Therefore, John is 6 years old in current time
