Answer:
5 + sqrt(65), 5 - sqrt(65)
Step-by-step explanation:
x + y = 10
x×y = -40
so, two equations with 2 variables. using one equation to express one variable by the second. and then using the second equation to solve and calculate the second variable. and then by knowing the second variable we calculate the first.
=> x = 10 - y
=> (10-y)×y = -40
=> -1×(10-y)×y = 40
=> (y-10)×y = 40
=> y^2 - 10×y - 40 = 0
remember the solution for a quadratic equation
a×x^2 + b×x + c
is
x = (-b ± sqrt(b^2 - 4×a×c)/(2×a)
in our case
a = 1
b = -10
c = -40
and we used "y".
so,
y = (--10 ± sqrt((-10)^2 - 4×1×(-40))/(2×1) =
= (10 ± sqrt(100 + 160))/2 = (10 ± sqrt(260))/2 =
= (10 ± sqrt (4×65))/2 = 10/2 ± 2×sqrt(65)/2 =
= 5 ± sqrt(65)
=>
for y = 5 + sqrt(65), x = 10 - 5 - sqrt(65) = 5 - sqrt(65)
for y = 5 - sqrt(65), x = 10 - 5 + sqrt(65) = 5 + sqrt(65)
Answer:
D
Step-by-step explaination:
Answer:
<h2>128m³</h2>
Step-by-step explanation:
Volume = L x W x H
L = 4
W = 4
H = 8
Volume = 4 x 4 x 8
Volume = 16 x 8 = 128m³
Hey there! :)
Answer:
First option: As x⇒ ∞ f(x) ⇒ -∞. As x⇒ -∞ f(x) ⇒ ∞.
Step-by-step explanation:
Rearrange the equation:
f(x) = -x³ - 2x² + 1
This is a negative cubic function. The function decreases over the interval
(-∞, ∞). Therefore:
As x⇒ ∞ f(x) ⇒ -∞.
As x⇒ -∞ f(x) ⇒ ∞.
This is the first option.
