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#7
+259
0
I'm aware more than you might suppose of what is even/uneven speaking both of numbers and functions.
The reason for my use of the term I chosed is already explained above.
"You had
tan theta = +-pi/6 + pi*n
I had
tan theta = +-pi/6 + 2pi*k OR (pi+-pi/6) + 2pi*k"
As far as I remember it's you who had sin and me who had tan.
Once again, may consider me futile but I can't get into your notation. Whether you have pi/6 or -pi/6 you have to add the period of tan function which is pi, not 2 pi. At least that's what I'd been taught. I think the notation have to be simplier,that is according to the main rules of roots notation. As for 5pi/6 or -5pi/6 or 9pi/6 or -9pi/6, the part "+ pi n" speaks for itself: you get all these angles when consecutively add other multiples of these original angles. When you have cos theta, then you have to insert either pi/6 or -pi/6. Since cos is "even" cos (-pi/6)= cos pi/6.
Homogeneous expression is the polynomial of which every term's sum of indexes of power is the same, for example, a^2 + ab + b^2. As a rule the equations of such a type are solved by dividing every term by the variable of the major power.
scrutinizer
Oct 22, 2013
#1
+259
0
The solution is quite simple: the angle of 45 degrees presumes that cos 45 : sin 45 = 1. The horizontal line stands here for cos 45, while the vertical one - the height - stands for sin 45. Since their aspect ratio is 1:1 then the height is also 19 meters.
scrutinizer
Oct 22, 2013
#4
+259
0
Misunderstanding of this kind happens often solely because of absence of elementary skill to present a task.
As for notation I've got accustomed to one being used in the Russian math elementaries, theory and practices. For example any term of arithmetic progression is denoted as an with arithmetic ratio denoted as d. Geometric progression - bn and q respectively.
scrutinizer
Oct 22, 2013
#3
+118725
+1
find a3 if a1=5584 r=-1/4
Well guest, is that what you meant.
It does sound reasonable, the notation that I am used to is a little different.
And, r usually stands for common ratio, which would make it a geometric progression.
I think the answer is more likely
a
3
= a
1
* r
(n-1)
a
3
= 5584 * (-1/4)
2
a
3
= 349
Melody
Oct 22, 2013
#2
+259
0
Isn't here easier just to recall the formula for cube of ratio that is (a - b)^3 = a^3 - b^3 - 3ab(a - b)?
scrutinizer
Oct 22, 2013
#2
+259
0
That's ok with that link, but what means "in a more advanced"? This forum is supposed to be the place where one could find the answers of any difficulty level he looks for. There're no such labels as "less advanced" put over here and if the person asks a question he most probably anticipates it to be answered without redirection to another link unless a person who tries to answer is not able to do this.
scrutinizer
Oct 22, 2013
#2
+259
0
We have an arithmetic progression here, where a1 is the first term and the third term is one to be found:
the progression is descending as arithmetical ratio is -1/4, so the third term is 5584 - 2*1/4. We used here the formula for calculating the nth term of arithmetic progression that is an = a1 + (n - 1)r.
scrutinizer
Oct 22, 2013
#1
+118725
+1
What is your real problem, don't you have a calculator?
I mean, do you want some help on entering it into your calculator or do you want to know how to do it without a calculator.
What is 5.8x10 to the 5 power x 6.4 x 10 to the 2 power
=5.8*6.4 * 10
5
* 10
2
=37.12 * 10
7
=3.712 * 10
8
Melody
Oct 22, 2013
#1
+118725
+1
Probability of an event = number of favourable outcomes / total number of possible outcomes
Melody
Oct 22, 2013
#1
+118725
0
A burn on a person’s skin is in the shape of a circle. If the radius of the burn is decreasing at the rate of 0.05 cm per day when it is 1.0 cm, what is the rate of decrease of the area of the burn at that instant?
A for area, t for time in days, r for radius in cm
A=pi*r
2
dA/dr = 2*pi*r
dr/dt = -0.05
dA/dt = (dA/dr) * (dr/dt) = 2*pi*r * -0.05 = -0.1*pi*r
When r=1,
dA/dt = -0.1*pi*1 = -0.1pi = -0.314
The instantaneous decrease in area is approx 0.314 cm
2
/day
Melody
Oct 22, 2013
#1
0
Question:
(1-x)^3
how does the above problem equal
-x^3 +3x^2 -3x +1
(1-x)^3 = (1-x)*(1-x)*(1-x)
We can then expand these brackets by multiplying the terms together.
The first two brackets multiplied together are below:
(1-x)*(1-x)
= (1*1) + (1*-x) + (1*-x) + (-x*-x)
= (1) + (-x) + (-x) + (x^2)
= 1 - 2x + x^2
re-inserting this back into the equation we see that:
(1-x)*(1 - 2x + x^2)
= (1*1) + (1*-2x) + (1*x^2) + (-x*1) + (-x*-2x) + (-x*x^2)
= (1) + (-2x) + (x^2) + (-x) + (2x^2) + (-x^3)
= 1 - 3x + 3x^3 - x^3
= -x^3 +3x^2 -3x +1
Hopefully this makes sense, if you need any clarification just ask.
Also any feedback on my way of explaining this would be greatly appreciated so I can better help people in the future.
Guest
Oct 22, 2013
#1
+118725
0
Factors of 39 are numbers go into 39 to give a whole answer.
There are 4 of them and you can find them by yourself.
Melody
Oct 22, 2013
#2
+118725
0
Answer is correct but if x>-3 and x<1 then
x must be between -3 and 1
so
-3<x<1
Melody
Oct 22, 2013
#1
+118725
0
this question really does not lend itself to elimination method but here it is.
This is just one way to go about elimination, there are other ways you could have gone about this.
multilply the first one by 2 and swap sides
2(-5/7-11/7*x)=-y*2
-10/7 - 22x/7 = -2y
-2y = -10/7 - 22x/7
So now the equations are
-2y = -10/7 - 22x/7 and
+2y = 7+5x
now add
-2y+2y = -10/7 + 7 - 22x/7 +5x
0 = -10/7 + 7 - 22x/7 +5x
It is easier now just to multiply everything by 7 and then to solve for x
Once you solve for x substitute it back into one of the original equations to get y.
Melody
Oct 22, 2013
#1
0
2529529080/(1.038)^2
Guest
Oct 22, 2013
#1
+118725
0
one quarter of the total
Melody
Oct 22, 2013
#1
+118725
0
Assuming that a zero can go anywhere I think it is
10^9
Melody
Oct 22, 2013
#1
0
go to this web site and it will help you http://www.webmath.com/redfract.html
Guest
Oct 22, 2013
#3
+118725
0
With repetition it is 10^5 = 100,000
Without repetition, but where order still matter, it is 10P5 = 30,240
I think that is right anyway.
Melody
Oct 22, 2013
#2
0
This is a vector math problem. Weight of 3 kg is directly down towards the ground.
a. The normal force is the force 90 degrees to the plane. Since the plane is at 40 degrees to the ground, the angle between the weight vector and the normal force is 50 degrees. From vector math, the normal force is 3 kg * cos(50) = 1.928 kg
b. The box is sitting still, so the force from friction keeping the box from moving down the slope is exactly equal, in the opposite direction, to the force of gravity trying to push the box down the slope. Since the plane is at 40 degrees to the ground, the force pointing down the slope is 3 kg * sin(50) = 2.298 kg. Since you want the horizontal component of this force, it is 2.298 kg * cos(40) = 1.760 kg
I wish I could draw the pictures. It has been a while since I did this sort for thing. I hope some one will check me.
Guest
Oct 22, 2013
#1
0
the answer is x>(or equal to)-3 and x<1
Guest
Oct 22, 2013
#2
0
Hi melody I'm sorry there's five digits
Guest
Oct 22, 2013
#1
+118725
0
How many digits in a zip code?
is it 0 to 9 that are used.
excuse my ignorance but I am not from USA.
Melody
Oct 22, 2013
#1
+118725
0
3x^2+x-2=0
3x
2
+ x = 2
3(x
2
+(1/3)x) = 2
x
2
+ (1/3)x = (2/3)
now [(1/3) divided by 2] squared = 1/36: add this to both sides
x
2
+ (1/3)x + (1/36) = 2/3 + 1/36
(x + 1/6)
2
= 25/36
x + 1/6 = +5/6 OR x + 1/6 = -5/6
and you can finish it.
Melody
Oct 22, 2013
#1
+118725
0
What is '_' ?
Melody
Oct 22, 2013
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