Все просто как бублик. (999+1)=1000, следующая пара (997+3)=1000 и т.д. Короче весде одни тысячи. Количество нечетных чисел от 1 до 500 равно 250 (половина четных, половина нечетных). Таким образом 1000 + 250 (количество пар нечетных чисел)= 250000 , т.е. ответ с.
C²=10²+3²
c²=100+9
c²=109
c=√109
а) Loq(4) sinπ/12 +1/3Loq³(4) sin13π/6+ Loq(4) sin7π/12 =
Loq(4) sinπ/12 +1/3Loq³(4) sin(2π+π/6)+ Loq(4) sin(π/2+π/12) =
Loq(4) sinπ/12 +1/3Loq³(4) sinπ/6+ Loq(4) cosπ/12 =
Loq(4) sinπ/12 +Loq(4) sinπ/6+ Loq(4) cosπ/12 =
Loq(4) sinπ/12 *cosπ/12 *sinπ/6) =Loq(4) (1/2)sinπ/6 *sinπ/6)=
Loq(4) (1/2)³ = Loq(2²) (2)^(-3) = -3/2 = -1,5.
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б) (1/2)Loq(8) (cosπ/8 -sinπ/8)² - Loq(8) (cosπ/8 +sinπ/8) ^(-1) =
|| т.к. cosπ/8 -sinπ/8 >0||
=((1/2)*2)Loq(8) (cosπ/8 -sinπ/8) - (-1)Loq(8) (cosπ/8 +sinπ/8)=
Loq(8) (cosπ/8 -sinπ/8) + Loq(8) (cosπ/8 +sinπ/8) =
Loq(8) (cosπ/8 -sinπ/8)*(cosπ/8 +sinπ/8) =Loq(8) (cos²π/8 -sin²π/8)=
Loq(8) cos2*(π/8) = Loq(8) cosπ/4 =Loq(8) 1/√2 = Loq(2³) 2^(-1/2) =
(-1/2)/3 = - 1/6.
1. (2-3у)² = 4-12y+9y².
2. (4-5а)(5а+4) = 16-25a².
3. (а-5)² = a²-10a+25.
4. (b+2)(b-2) = b²-4.
<span>5. (7x²-6y)(7x²+6y) = 49x</span>⁴-36y².