Function Operations Practice - 12/10/2020 MAT 120

Function Operations Practice - 12/10/2020 MAT 120

Multiple Choice

Given

f(x) = 3x² + 7x and g(x) = 2x² - x - 1, find (f + g)(x).

• 11x² - 1

• 5x⁴ + 6x² - 1

• 5x² + 6x - 1

• 5x² + 8x - 1

Multiple Choice

f(x) = x²+9

g(x) = x-9

Find f(x)-g(x).

• x²+x+9

• x²-x+9

• x²-x

• x²-x+18

Multiple Choice

Find f(2).

 $If\ f\left(x\right)\ =\ 2x^2-5x\ and\ g\left(x\right)\ =3x^2$  

• -2

• -18

• 24

• 6

Multiplying Functions

• Use FOIL

• Use the box/punnett square

• Distribute everything to everything! :-)

Multiple Choice

f(x) = 4x+8

g(x) = x+3,

Find f(x) * g(x)

• 4x²+24

• 4x²+20x+24

• 4x²+12x+24

• 4x²+4x+24

Dividing Polynomials (Recap from yesterday)

• Factor the numerator. Often the polynomial that starts with x².

• Find the factors of the end number that add to the middle.

• **ax²+bx+c (find the factors of "c" that add to b")

• Look for the factor that cancels out with the denominator

• The leftover term is your answer.

Poll

Consider this function. What is the middle term? What is "b"?  $x^2-9$  

• 0

• 1

• -9

Poll

What are the factors of -9 that add up to 0?

• 3, -3

• 9, -1

• 0, 9

Multiple Choice

So what are the factors of $x^2-9$  ?

• (x-1)(x+9)

• (x-3)(x+3)

• (x-9)(x+1)

Multiple Choice

 $f\left(x\right)=x^2-4x-32$  

and  $g\left(x\right)=x+4$  . What is  $\frac{f\left(x\right)}{g\left(x\right)}$  ?

• x-12

• x+4

• x-8

• x-3

Open Ended

What is  $\frac{f\left(x\right)}{g\left(x\right)}$  ?

 $f\left(x\right)=x^2-7x-30\ and\ g\left(x\right)=x+3$  

You're all done! Read the reminders & work on your DeltaMath until class ends.

• Check DeltaMath daily

• Friday assignment is to complete this week's work

• Check Schoology for office hours tomorrow. We are here to help!