SRL Archive - Mathematics

I need some help with a certain problem.
The question is:


Where I is a certain angle, and n is the number of sides.
I have to find the number of sides a polygon has by using the given angle (108). (Just have to sub 108 into I)

I got the answer:
as the inverse

However, this equation also results in the correct answer:

The correct answer is 5/Pentagon.
Are they both right? Am I wrong?

Correct way to solve: http://puu.sh/2tQch

yours is wrong

Solve for n:
(180 (n-2))/n = i
Multiply both sides by a polynomial to clear fractions.
Multiply both sides by n:
180 (n-2) = i n
Write the linear polynomial on the left hand side in standard form.
Expand out terms of the left hand side:
180 n-360 = i n
Isolate n to the left hand side.
Subtract -360+i n from both sides:
(-i+180) n = 360
Solve for n.
Divide both sides by 180-i:
Answer: |
| n = (360 i)/32401+64800/32401

On my phone doing wolfram

@masterBB , what software do you use for visulisation or do u use mathML/LaTeX

From: Enslaved
@masterBB , what software do you use for visulisation or do u use mathML/LaTeX

People ask me that a lot. I simply use Microsoft Word.

Sin, you're making the mistake of thinking you need to form the inverse of the function, which you don't need to do at all. When you inverse a function, it actually become an entirely different thing (it's actually a reflection in y=x).

What you need to do is simply sub the value of i in:

108 = 180 - 360/n
-72 = -360/n (minus 180)
-72n = -360 (time by n)
-n = -5 OR n = 5 (divide by 72 [or -72])

Damn <.<
Gg 2marks..