Answer:
A.) gf(x) = 3x^2 + 12x + 9
B.) g'(x) = 2
Step-by-step explanation:
A.) The two given functions are:
f(x) = (x + 2)^2 and g(x) = 3(x - 1)
Open the bracket of the two functions
f(x) = (x + 2)^2
f(x) = x^2 + 2x + 2x + 4
f(x) = x^2 + 4x + 4
and
g(x) = 3(x - 1)
g(x) = 3x - 3
To find gf(x), substitute f(x) for x in g(x)
gf(x) = 3( x^2 + 4x + 4 ) - 3
gf(x) = 3x^2 + 12x + 12 - 3
gf(x) = 3x^2 + 12x + 9
Where
a = 3, b = 12, c = 9
B.) To find g '(12), you must first find the inverse function of g(x) that is g'(x)
To find g'(x), let g(x) be equal to y. Then, interchange y and x for each other and make y the subject of formula
Y = 3x + 3
X = 3y + 3
Make y the subject of formula
3y = x - 3
Y = x/3 - 3/3
Y = x/3 - 1
Therefore, g'(x) = x/3 - 1
For g'(12), substitute 12 for x in g' (x)
g'(x) = 12/4 - 1
g'(x) = 3 - 1
g'(x) = 2.
To find this, turn the word question into an equation.
"One less than" means - 1, which is 1 being subtracted from something.
"half a number" means 1/2x, since 1/2 is half and x is unknown.
"is 12" means = 12, which is something equals 12.
Putting this in order would be 1/2x, then - 1, then = 12.
As an equation, this is 1/2x - 1 = 12.
So the equation is 1/2x - 1 = 12
Now you must find the number by solving this equation.
1/2x - 1 = 12
First, add 1 to both sides.
12 + 1 = 13
1/2x = 13
Now multiply both sides by 2.
This way, x will be isolated since 1/2x • 2 = 1x, and 1x = x.
13 • 2 = 26
x = 26
The number is 26.
Answer:
13x^2 - 15x + 12
Step-by-step explanation:
Add like terms.
3x^2 + 10x^2 = 13x^2
-10x + -5x = -15x
4 + 8 = 12
