Jason (5 Radium)
Photo
Let x=length of the rectangle
h = height of the rectangle
Black line = h/tan(60°) = (h√3)/3
Using Pythagoras' Theorem,
[(h√3)/3 + x]² + h² = 36
h²/3 + (2xh√3)/3 + x² + h² - 36 = 0
h²(4/3) + [(2x√3)/3]h + (x²-36) = 0
h = [-(2x√3)/3 + √[(4x²/3)-(16/3)(x²-36)]]/(8/3)
h = [-x√3 + 3√(48-x²)]/4
Area of the rectangle, A = xh = x([-x√3 + 3√(48-x²)]/4)
dA/dx = (72-3x²-x√(144-3x²))/(2√(48-x²))
At Maximum, dA/dx = 0
(72-3x²-x√(144-3x²))/(2√(48-x²)) = 0
72-3x²-x√(144-3x²) = 0
=> x=-6 or x=2√3
Max A = 6√3
h = height of the rectangle
Black line = h/tan(60°) = (h√3)/3
Using Pythagoras' Theorem,
[(h√3)/3 + x]² + h² = 36
h²/3 + (2xh√3)/3 + x² + h² - 36 = 0
h²(4/3) + [(2x√3)/3]h + (x²-36) = 0
h = [-(2x√3)/3 + √[(4x²/3)-(16/3)(x²-36)]]/(8/3)
h = [-x√3 + 3√(48-x²)]/4
Area of the rectangle, A = xh = x([-x√3 + 3√(48-x²)]/4)
dA/dx = (72-3x²-x√(144-3x²))/(2√(48-x²))
At Maximum, dA/dx = 0
(72-3x²-x√(144-3x²))/(2√(48-x²)) = 0
72-3x²-x√(144-3x²) = 0
=> x=-6 or x=2√3
Max A = 6√3
Jason (5 Radium)
Photo
day 1 of studying addmaths everyday...🔥🔥 make sure u do 3 questions atleast a day...
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Forwarded from Sembang Maths
Percayalah cakap saya, mula lah sekarang. Jangan tunggu saat akhir. Pesanan yang sama dari saya, sebab saya dah tengok pelbagai situasi pelajar saat2 last nak spm
👍10❤6
Forwarded from K.Y. Chan
Recently I saw a few videos talking about ambiguous case of the law of sine for solutions of triangle.
Question: When you are learning this topic, do you find it difficult to understand it? And why?
Question: When you are learning this topic, do you find it difficult to understand it? And why?
Anonymous Poll
29%
Easy to understand
26%
Hard to understand
45%
Know what to do, but do not understand the concept
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Forwarded from AddMath Spmnetic!™⚡️ (Jason (4 Radium))
❤3👏1
Given f(x) = 3x² − 12x + 5, what is the minimum value of f(x)?
Anonymous Quiz
56%
-7
15%
-5
22%
5
7%
7
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Kenapa B) −5 salah ❌
Terlupa darab 3 × 4 = 12. Ramai yang guna 10 instead of 12 masa buat complete the square
Terlupa darab 3 × 4 = 12. Ramai yang guna 10 instead of 12 masa buat complete the square
Kenapa C) 5 salah❌
Terus ambil nilai pemalar +5 je tanpa buat full working. Nilai minimum bukan bermakna nilai pemalar!
Kenapa D) 7 salah ❌
Silap tanda! Jawapan dapat −7 tapi tulis +7. Jangan terlupa semak tanda positif dan negatif! 😭
Terus ambil nilai pemalar +5 je tanpa buat full working. Nilai minimum bukan bermakna nilai pemalar!
Kenapa D) 7 salah ❌
Silap tanda! Jawapan dapat −7 tapi tulis +7. Jangan terlupa semak tanda positif dan negatif! 😭
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