Math World
18.7K posts

Math World
@Math_World_
Community of teaching and learning mathematics via daily math&geo questions.
İstanbul, Türkiye Tham gia Mayıs 2017
2.4K Đang theo dõi30.9K Người theo dõi

@mathhub_vn @karadagmetin2 Higher than Shaquille O'Neal, shorter than Sultan Kösen
Dansk

@Math_World_ A=1 + 2 + 2² + 2³ + ···+ 2²⁴
=1・[( 2 ²⁵ - 1 )/( 2 - 1)]
= 2 ²⁵ - 1 ― ①
Substitute ① for ②.
√ log( A + 1 )/ log 2 ― ②
=√ log ( 2 ²⁵ - 1 + 1 )/ log 2
=√( 25 log 2 )/ ( log 2 )
=√ 25
=5
English

@Math_World_ A + 1 = 33.554.432 = 2²⁵log₂(A + 1) = log₂(2²⁵) = 25
√((log(A+1)) / log(2)) = √(log₂(A+1)) = 5
English

@Math_World_ U´・ω・`U
x+y=15/2 ⋯ ①
x・y=9 ⋯ ② (→ x≠0, y≠0)
②/x →
y=9/x ⋯ ③ → ①
x+(9/x)=15/2 →
2x^2-15x+18=0
(2x-3)(x-6)=0
∴ x=3/2, 6 → ③
∴(x, y)=(3/2, 6), (6, 3/2)

@Math_World_ x + y = 15/2
xy = 9
t² – (15/2)t + 9 = 0
2t² – 15t + 18 = 0
Δ = 225 – 144 = 81
√Δ = 9
t = (15 ± 9)/(2·2) = (15 ± 9)/4
t₁ = 24/4 = 6
t₂ = 6/4 = 3/2
x = 6, y = 3/2 ou x = 3/2, y = 6


















