Answer:
The minimum value of f(x) is -21 and it occurs at x = 1
Step-by-step explanation:
f(x) =3x^2-6x-18
Factor out the greatest common factor out of the first two terms
f(x) =3(x^2-2x)-18
Complete the square
-2x/2 =-1 (-1)^2 = 1
Add 1 (But remember the 3 out front so we are really adding 3 so we need to subtract 3 to remain balanced)
f(x) = 3(x^2 -2x+1) -3 -18
f(x) = 3(x-1)^2 -21
This is vertex form
f(x) = a(x-h)^2 +k where (h,k) is the vertex and a is a constant
The vertex is (1,-21)
Since a > 0 this opens upward and the vertex is a minimum
The minimum value of f(x) is -21 and it occurs at x = 1
FOIL is a mnemonic rule for multiplying binomial (that is, two-term) algebraic expressions.
FOIL abbreviates the sequence "First, Outside, Inside, Last"; it's a way of remembering that the product is the sum of the products of those four combinations of terms.
For instance, if we multiply the two expressions
(x + 1) (x + 2)
then the result is the sum of these four products:
x times x (the First terms of each expression)
x times 2 (the Outside pair of terms)
1 times x (the Inside pair of terms)
1 times 2 (the Last terms of each expression)
and so
(x + 1) (x + 2) = x^2 + 2x + 1x + 2 = x^2 + 3x + 2
[where the ^ is the usual way we indicate exponents here in Answers, because they're hard to represent in an online text environment].
Now, compare this to multiplying a pair of two-digit integers:
37 × 43
= (30 × 40) + (30 × 3) + (7 × 40) + (7 × 3)
= 1200 + 90 + 280 + 21
= 1591
The reason the two processes resemble each other is that multiplication is multiplication; the difference in the ways we represent the factors doesn't make it a fundamentally different operation.
Answer:
28 questions
Step-by-step explanation:
In the first 10 mins she answered 2/5 of 40 which is 16. The remaining amount is 24 questions and half of that is 12. So she answered 12 questions in 15 mins. Finally you add them to get 28 questions in 25 minutes.
Ahiffggggggggggggt was the morning I was going over the
