Simplifying
4x3 + -81x = 0
Reorder the terms:
-81x + 4x3 = 0
Solving
-81x + 4x3 = 0
Solving for variable 'x'.
Factor out the Greatest Common Factor (GCF), 'x'.
x(-81 + 4x2) = 0
Factor a difference between two squares.
x((9 + 2x)(-9 + 2x)) = 0
Subproblem 1
Set the factor 'x' equal to zero and attempt to solve:
Simplifying
x = 0
Solving
x = 0
Move all terms containing x to the left, all other terms to the right.
Simplifying
x = 0
Subproblem 2
Set the factor '(9 + 2x)' equal to zero and attempt to solve:
Simplifying
9 + 2x = 0
Solving
9 + 2x = 0
Move all terms containing x to the left, all other terms to the right.
Add '-9' to each side of the equation.
9 + -9 + 2x = 0 + -9
Combine like terms: 9 + -9 = 0
0 + 2x = 0 + -9
2x = 0 + -9
Combine like terms: 0 + -9 = -9
2x = -9
Divide each side by '2'.
x = -4.5
Simplifying
x = -4.5
Subproblem 3
Set the factor '(-9 + 2x)' equal to zero and attempt to solve:
Simplifying
-9 + 2x = 0
Solving
-9 + 2x = 0
Move all terms containing x to the left, all other terms to the right.
Add '9' to each side of the equation.
-9 + 9 + 2x = 0 + 9
Combine like terms: -9 + 9 = 0
0 + 2x = 0 + 9
2x = 0 + 9
Combine like terms: 0 + 9 = 9
2x = 9
Divide each side by '2'.
x = 4.5
Simplifying
x = 4.5
Solution
x = {0, -4.5, 4.5}
1. Найдите сумму бесконечно убывающей геометрической прогрессии 36: 12; 4; ...;
b1=36
b2=12
b3=4
q=b2/b1
s=b1/(1-q)
q=-12/36=-1/3
s=36/(1+1/3)=36/(4/3)=36*3/4=27
ответ: 27
2. Сумма бесконечно убывающей геометрической прогрессии равна 54. Найти, если
Если...? Тут как будто какого-то условия не хватает ((
3. Найдите сумму и первых членов арифметической прогрессии, если а=1, an=200, n=100
Sn = (a1 + an)/2* n
a1 = 1
an = 200
n = 100
S100 = (1 + 200)/2*100 = 201*50 = 10050
ответ: 10050
Объяснение:
Проверь второе задание, там будто реально условия не хватает.
Поделитесь своими знаниями, ответьте на вопрос:
Нужно найти наибольшее значение функции: y=6корней из2cosx+6x-3п/2-9 на отрезке [0; п/3]
-6sqrt(2)sinx+6=0
sinx=sqrt(2)/2
x=п/4
y(0)=6sqrt(2)-9-3п/2< 0
y(п/4)=6+6п/4-3п/2-9=-3
y(п/3)=3sqrt(2)-9-3п/2+2п=3sqrt(2)-9+п/2
6sqrt(2)-9-3п/2-3sqrt(2)+9-п/2=3sqrt(2)-2п< 0
3sqrt(2)-9+п/2+3=3sqrt(2)-6+п/2< 0
y(п/4)=-3 max