1.
а = с * sinα,
a = 26 * sin 67°23' = 26 * 0,9231 = 24,
b = c * cosα,
b = 26 * 0,3846 = 10,
2.
c = b : sinβ,
c = 28 : 0,5282 = 53,
a = √(c² - b²),
a = √(53² - 28²) = √(2809 - 784) = √2025 = 45,
3.
b = √(c² - a²),
b = √(29² - 21²) = √(841 - 441) = √400 = 20,
4.
c = b : cosα,
c = 63 : 0,9689 = 65,
a = √(c² - b²),
a = √(65² - 63²) = √(4225 - 3969) = √256 = 16
(10n + 5)² = 100n(n + 1) + 25
Воспользуемся формулой квадрата суммы
100n² + 100n + 25 = 100n² + 100n + 25
а) 35² = (30 + 5)² = 900 + 300 + 25 = 1225
б) 55² = (50 + 5)² = 2500 + 500 + 25 = 3023
в) 85² = (80 + 5)² = 6400 + 800 + 25 = 7225
г) 125² = (100 + 25)² = 10000 + 5000 + 625 = 15625
1/(0,5+cos(270-60))+1/(0,5-sin(180-60))=1/(0,5-sin60)+1/(0,5-sin60)=
=2/(0,5-sin60)=2:(1/2-√3/2)=2:(1-√3)/2=2*2/(1-√3)=4(1+√3)/(-2)=
=-2(1+√3)=-2-2√3
Ответ 1