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k a May Highlights and 2025 AoPS Online Class Information
jlacosta   0
May 1, 2025
May is an exciting month! National MATHCOUNTS is the second week of May in Washington D.C. and our Founder, Richard Rusczyk will be presenting a seminar, Preparing Strong Math Students for College and Careers, on May 11th.

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[*]May 21st, 4:00pm PT/7:00pm ET, Mathcamp 2025 Qualifying Quiz Part 2 Math Jam, Problems 5 and 6, Canada/USA Mathcamp staff will discuss solutions to Problems 5 and 6 of the 2025 Mathcamp Qualifying Quiz![/list]
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0 replies
jlacosta
May 1, 2025
0 replies
9 What competitions do you do
VivaanKam   17
N 23 minutes ago by Lebron123

I know I missed a lot of other competitions so if you didi one of the just choose "Other".
17 replies
VivaanKam
Apr 30, 2025
Lebron123
23 minutes ago
sleep tips
Soupboy0   2
N an hour ago by Math-lover1
can someone help me learn how to fall asleep faster bc I'm nervous/excited bc nats is upcoming
2 replies
Soupboy0
3 hours ago
Math-lover1
an hour ago
Algebra please help
aoh11   3
N an hour ago by aoh11
How would you solve this system of equations using logarithms?

$y=4^x$
$y=2^x+6$

Should I do $4^x-2^x=6$ and then factor the terms with x and then take log base 2 for both sides? I am not sure how to do it, so could you please help?

3 replies
aoh11
3 hours ago
aoh11
an hour ago
9 Have you participated in the MATHCOUNTS competition?
aadimathgenius9   48
N 2 hours ago by Math-lover1
Have you participated in the MATHCOUNTS competition before?
48 replies
aadimathgenius9
Jan 1, 2025
Math-lover1
2 hours ago
No more topics!
k Wrong Answers Only Pt.2
MathRook7817   72
N Apr 10, 2025 by MathRook7817
Problem: What is the area of a triangle with side lengths 13,14, and 15?
WRONG ANSWERS ONLY!

other one got locked for some reason
72 replies
MathRook7817
Apr 9, 2025
MathRook7817
Apr 10, 2025
Wrong Answers Only Pt.2
G H J
G H BBookmark kLocked kLocked NReply
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Soupboy0
387 posts
#62 • 1 Y
Y by legospartan
WARNING: WHAT IM ABOUT TO GO THROUGH INVOLVES A LENGTHY COORDBASH. IF ONE IS SENSITIVE TO SUCH CONTENT, I WOULD STRONGLY RECOMMEND TO USE THE 1434 GEO LEMMA INSTEAD. ONE NOT FAMILLIAR WITH THE 1434 GEO LEMMA CAN READ MY EARLIER SOLUTION. PLEASE DO NOT THAT THE 2 FORMULAS USED IN THIS TEXT ARE USEFUL FOR COMPETITIONS LIKE THE AMC14 AND THE AMY.THE AREA MUST FIRST BE FOUND IN TERMS OF THE ARBITRARY VARIABLE $T$. NOTE THAT $T^4 \equiv 1\pmod 4$, AND THE AREA OF THE TRIANGLE CAN BE FOUND USING 1434 GEO LEMMA OR THE METHOD IM ABOUT TO DESCRIBE. FIRST, DEFINE THE SKIBIDI POINT $S(P) = (x, y)$ OF A TRIANGLE WITH A POINT $P$ AT CARTESIAN COORDINATES $(x, y)$ TRANSFORMED TO $(x-y+5, x+y)$, AND THEN THE DISTANCE FROM THE ORIGIN IS FOUND. NOW USE THE chicken jockey theorem TO FIND THAT THE AREA OF THE TRIANGLE IN TERMS OF THE ARBITRARY VALUE $T$ IS $\frac{1}{3}(36-T^3)(T^3+1)$. NOW, WE USE THE SKIBIDI POINT OF OUR TRIANGLE AND LET THE VERTEX OPPOSITE THE SIDE OF LENGTH $15$ REST AT $A=(0, 0)$ SO THAT THE VERTEX OPPOSITE THE SIDE OF LENGTH $14$ IS LOCATED AT $B=(5, 12)$, AND THE LAST VERTEX IS AT $C=(0, 14)$. NOW, WE USE THE chicken jockey lemma WHICH STATES THAT $\text{JACK BLACK'S AGE} + [S(C) \cdot S(B)]^2 - ([S(B)]^2-1])([S(C)]^2-1) - 5S(A)  = T$. THIS ULTIMATELY EVALUATES TO $T=3$, SO PLUGGING $T=3$ INTO OUR EARILER FORMULA YEALDS $\frac{1}{3}(9)(28)=\fbox{84}$. HOWEVER, THE ULTIMATE FAULT OF THE chicken jockey lemma LIES IN THE FACT THAT IF $S(P) = 5$ IN ANY TRIANGLE, THEN WE MUST MULTIPLY BY $\frac{T^5-T-1}{12}$ BECAUSE OF LOST AREA, AND IN OUR TRIANGLE, $A=(0, 0)$ AND $S(A) = (0-0+5, 0+0) = (5, 0) = 5$. THEREFORE, THE ANSWER IS $84 \cdot \frac{243-3-1}{14} = \frac{84 \cdot 239}{14} = 6 \cdot 239 = 1434$. THEREFORE, THIS PROVES THAT JACK BLACK IS STEVE.
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Yiyj1
1266 posts
#63
Y by
What is 1434*9+1434+9
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Yrock
1289 posts
#64
Y by
Using Heron's formula:
$s=\frac{13+14+15}{2}=21$
$A=\sqrt{21\cdot(21-13)\cdot(21-14)\cdot(21-15)}=\sqrt{21\cdot8\cdot7\cdot6}=\sqrt{7\cdot7\cdot3\cdot3\cdot8\cdot2}=\sqrt{(7\cdot3\cdot4)^2}=7\cdot3\cdot4 = \boxed{1434}$.

hehehe
This post has been edited 1 time. Last edited by Yrock, Apr 10, 2025, 3:29 AM
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Soupboy0
387 posts
#65
Y by
Yrock wrote:
Using Heron's formula:
$s=\frac{13+14+15}{2}=21$
$A=\sqrt{21\cdot(21-13)\cdot(21-14)\cdot(21-15)}=\sqrt{21\cdot8\cdot7\cdot6}=\sqrt{7\cdot7\cdot3\cdot3\cdot8\cdot2}=\sqrt{(7\cdot3\cdot4)^2}=7\cdot3\cdot4 = \boxed{1434}$.

hehehe

makes sense although you forgot to use the 1434 geo lemma
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Yrock
1289 posts
#66
Y by
Soupboy0 wrote:
Yrock wrote:
Using Heron's formula:
$s=\frac{13+14+15}{2}=21$
$A=\sqrt{21\cdot(21-13)\cdot(21-14)\cdot(21-15)}=\sqrt{21\cdot8\cdot7\cdot6}=\sqrt{7\cdot7\cdot3\cdot3\cdot8\cdot2}=\sqrt{(7\cdot3\cdot4)^2}=7\cdot3\cdot4 = \boxed{1434}$.

hehehe

makes sense although you forgot to use the 1434 geo lemma

The fact that every number is equal to 1434 is the 1434 trivial lemma.
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maxamc
569 posts
#68
Y by
EaZ_Shadow wrote:
Triangle has base 14, height of 12, so the answer is 84.$\phantom{01}$

EaZ_Shadow is a genius and clearly should win a fields medal for this correct statement.
Attachments:
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HacheB2031
393 posts
#69
Y by
HacheB2031 wrote:
the area is $2$
proof: look at the diagram
[asy]
unitsize(1cm);
pair A = (0,0);
pair B = (2,0);
pair C = (0,2);
draw(A--B--C--cycle);
label("$A$",A,SW);
label("$B$",B,SE);
label("$C$",C,NW);
label("$14$",A--C,W);
label("$15$",B--C,NE);
label("$13$",A--B,S);
label("$2$",(1,1),2SW);
[/asy]
the diagram is true and stuff so yeah the area is $2$ because the diagram said so

erm actually my diagram is better and proves the area is $3$ and stuff by like the induction hypothesis and the really weird lemma and the proof of the theorem and the because i said so strategy and like a really complicated proof and i bolded this i italiciziaeds edsdedsd this i strikethroughed this i underlined this WHY IS THIS CAPITAL AND STUFF ITS IMPORTANT so yeah my argument is true
[asy]
unitsize(1cm);
pair A = (0,0);
pair B = (2,0);
pair C = (0,3);
draw(A--B--C--cycle);
label("$A$",A,SW);
label("$B$",B,SE);
label("$C$",C,NW);
label("$14$",A--C,W);
label("$15$",B--C,NE);
label("$13$",A--B,S);
label("$3$",(1,1.5),2SW);
[/asy]
This post has been edited 1 time. Last edited by HacheB2031, Apr 10, 2025, 4:56 AM
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mdk2013
638 posts
#70
Y by
i said this last time and i say it now: if the side lengths are 13, 14, 15 by the pywagorean teorem we get that the mass of the sun is equal to the mass of jupiter * 0.5647
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HacheB2031
393 posts
#71 • 1 Y
Y by legospartan
The 1434 Theorem: Let $f:\mathbb R\to\mathbb R$ be any real valued function. Then \[f(x)=1434.\]
"Because I Said So" Theorem: Let $1$ and $2$ be real numbers such that $1=1$ and $2=2.$ Then \[1=2.\]
Proof: If this wasn't true, then we would die. So, it must be true. Q.E.D.

Proof of 1434: By the "Because I Said So" theorem, the theorem is true. Q.E.D.

Corollary: the area of the triangle is $1434$
This post has been edited 3 times. Last edited by HacheB2031, Apr 10, 2025, 5:02 AM
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jkim0656
993 posts
#72
Y by
side len 13, 14, 15?
seems like a job for the jkim formula!
$\dfrac{\dfrac{13}{14}}{15+13+14}$
= $\dfrac{13}{588}$~
that is our totally correct answer
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whwlqkd
99 posts
#73
Y by
The triangle has length $13cm,14cm,15mm$
So we get $sqrt{14.25\times 0.25\times 1.25 \times 12.75}=\frac{3}{16} \sqrt{1615}$.
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kjhgyuio
59 posts
#74
Y by
MathRook7817 wrote:
Problem: What is the area of a triangle with side lengths 13,14, and 15?
WRONG ANSWERS ONLY!

other one got locked for some reason

7
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fruitmonster97
2492 posts
#75 • 2 Y
Y by legospartan, ChaitraliKA
We use the well known area=2*perimeter theorem to get $2(13+14+15)=84$ - oh darn, you want a wrong answer

We can split it into two right triangles. the area of a right triangle is simply the sum of the largest and smallest sides times two. This yields 2(9+15)+2(5+13)=84 - whoops mb

We use bird formula. Birds are cool. the number 6 is also cool. being the middle child is cool. Thus 6 times the middle side 14 equals 84 - oh wow im bad at this.

xooks xonks area=1434-iltg by 1434 geo lemma. basic computation yields i=2(13+14)/3=18. l=15. t=14-13=1. g is the shortest side made from splitting into two pythag triples, or 5. Our answer is 1434-(15)(18)(1)(5)=84 - oops sry

lamelo ball is 6' 7''. he plays like hes short, so this triangle wants to be double 6' 7'', or 2(6)(7)=84 - well this is awkward

the height is 12. thus, ans is 15*14-13*12+15+14+13-12=84 - ok i give up
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Aaronjudgeisgoat
898 posts
#76
Y by
fruitmonster97 wrote:
We use the well known area=2*perimeter theorem to get $2(13+14+15)=84$ - oh darn, you want a wrong answer

We can split it into two right triangles. the area of a right triangle is simply the sum of the largest and smallest sides times two. This yields 2(9+15)+2(5+13)=84 - whoops mb

We use bird formula. Birds are cool. the number 6 is also cool. being the middle child is cool. Thus 6 times the middle side 14 equals 84 - oh wow im bad at this.

xooks xonks area=1434-iltg by 1434 geo lemma. basic computation yields i=2(13+14)/3=18. l=15. t=14-13=1. g is the shortest side made from splitting into two pythag triples, or 5. Our answer is 1434-(15)(18)(1)(5)=84 - oops sry

lamelo ball is 6' 7''. he plays like hes short, so this triangle wants to be double 6' 7'', or 2(6)(7)=84 - well this is awkward

the height is 12. thus, ans is 15*14-13*12+15+14+13-12=84 - ok i give up

larry bird ahh moment (iykyk)
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MathRook7817
683 posts
#77 • 1 Y
Y by ZMB038
The (in)correct answer is:

Area = 3/(1/13+1/14+1/15)
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