Function Operations

Evaluate functions

100

Let f(x)=4x-1 and g(x)=2x²+3. Then f(2)+g(2) equals what?

f(2) = 7
g(2) = 11

f(2)+g(2) = 18.

200

Let f(x)=4x-1 and g(x)=2x²+3. Then g(3)-f(3) equals what?

g(3) = 21

f(3) = 11

g(3) - f(3) = 10

300

Let f(x)=x²-5 and g(x)=3x+2. Then (f*g)(-2) equals what?

f(-2) = -1
g(-2) = -4

(fg)(-2) = 4

400

Let f(x)=3x²+2 and g(x)=2x. Then f(g(4)) equals what?

g(4) = 8 ->  f(8) = 194

500

Let f(x)=3x and g(x)=2x+4. Then (f (g(1)) equals what?

g(1) = 6 -> f(6) = 18

Add/Subtract

100

Let f(x)=4x-1 and g(x)=2x²+3. Then (f+g)(x) equals what?

What is 2x² + 4x + 2

200

Let f(x)=-3x+2 and g(x)=5-x. Then (f-g)(x) equals what?

-3x+2-(5-x)
-3x+2-5+x

What is -2x-3

300

Let f(x)=3x+5 and g(x)=x². Then f(x)+g(x) equals what?

What is x² + 3x + 5

400

Let f(x)=3x-5 and g(x)=x². Then f(x)+f(x) equals what?

What is 6x-10

500

Let f(x)=x²-5 and g(x)=3x+2. Then (f-g)(x) equals what?

x²-5-(3x+2) = x²-5-3x-2

What is x²-3x-7

Multipy/Divide

100

Let f(x)=4x-1 and g(x)=2x²+3. Then (fg)(x) equals what?

(4x-1)(2x²+3)

What is 8x³ - 2x² + 12x - 3

200

Let f(x)=3x+5 and g(x)=x². Then (fg)(x) equals what?

What is 3x³ + 5x²

300

Let f(x)=2x²+x-3 and g(x)=x-1. Then f/g(x) equals what? State the domain.

(2x^2 +x-3)/(x-1) 

Domain: all real except x = 1

400

Let f(x)=x²-5 and g(x)=3x+2. Then (f/g)(x) equals what?

(x^2-5)/(3x+2)

Domain: all real except x = -2/3

500

Let f(x)=2x²+4x-3 and g(x)=x-3. Then (fg)(x) equals what?

What is 2x³ - 2x² -15x + 9

Composite Functions

100

Let f(x)=3x²+2 and g(x)=2x. Then f(g(x)) equals what?

3(2x)²+2
3(4x²)+2

What is 12x² + 2

200

Let f(x)=3x²+2 and g(x)=2x. Then g(f(x)) equals what?

What is 6x² + 4

300

Let f(x)=3x and g(x)=2x+4. Then (f o g)(x) equals what?

(f o g)(x) = f(g(x))

3(2x+4) = 6x+12

400

Let f(x)=3x² and g(x)=2x+4. Then g(f(x)) equals what?

2(3x²)+4

6x²+4

500

Let f(x)=3x² and g(x)=2x+4. Then f(g(x)) equals what?

3(2x+4)² = 3(2x+4)(2x+4)

3(4x²+16x+16) = 12x²+48x+48