Solve for n: 119 = n^2 - 3n / 2

  • Thread starter Thread starter get_rekd
  • Start date Start date
AI Thread Summary
To find the number of sides of a polygon with 119 diagonals, the equation 119 = (n^2 - 3n) / 2 is used. Rearranging this gives 238 = n^2 - 3n, leading to the quadratic equation n^2 - 3n - 238 = 0. The quadratic formula can then be applied to solve for n. This process will yield the number of sides in the polygon. The discussion emphasizes the correct setup and solving of the quadratic equation.
get_rekd
Messages
39
Reaction score
0
d=n^2 - 3n / 2

where d = number of diagonals
and n = the number of sides of the polygon.

A polygon has 119 diagonals, how many sides does it have?

119 = n^2 - 3n / 2

I am not sure how to do this? can someone please help?

sorry this isn't physics related

I know I need to use the quadratic formula, but how?
 
Physics news on Phys.org
d=n^2 - 3n / 2 this should be d = ( n^2 - 3n)/2
Wright the given equation 119 = n^2 - 3n / 2 as 2*119 = n^2 - 3n and solve the quadritic equation to get the value of n.
 
thank you very much
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Solve a Quick Math Question: How Many Sides in a Polygon w/ 119 Diagonals?
Replies
2
Views
3K
A polygon is rolling down a hill
Replies
3
Views
1K
Dispersion of rightward steps in 1-D random walks
Replies
3
Views
534
Focussing a collimated beam using a diffraction grating
Replies
1
Views
661
QFT: Normalization of coherent states
Replies
2
Views
2K
Loop the Loop Problem Solution | N > 0, Energy Conservation Method
Replies
8
Views
3K
Questions about a habitable second moon
Replies
37
Views
6K
Projectile motion with ##N## bounces on the ground
Replies
21
Views
960
Writing a vector parallel and normal to a unit vector ##\hat n##
Replies
26
Views
1K
Proving convergence of rational sequence
Replies
2
Views
1K

Hot Threads

Recent Insights

Back
Top