Question

Compound functions:
f(x)=2x^2-5
and
g(x)=x^2-3x+1

Find: (f+g)(1)
I got 3x^2-3x-4. Is that right??

Find: (f-g)(-2)
How do I even do this one? I got-2x^2-6xx+12

Find: (f*g)(4)
I have no idea but I got 8x^4-24x^3-12x^2+60x-20

Find: (f/g)(1.5)
I don't even know where to begin with this one. Do I use polynomial division or something?

Answer 1

That's either Advanced 8th grade math, or Freshman year Algebra...

Answer 2

\[(f+g)(x)=f(x)+g(x)\]so\[(f+g)(1)= f(1)+g(1)\]For f(1) plug in 1 in the place of x in the expression given for f(x)\[f(1)= 2\times1^2-5=-3\]Similarly solve for g(1) and add for (f+g)(1).
For the other parts follow similar steps using the following relations:
\[(f-g)(x)= f(x)-g(x)\]\[(f*g)(x)=f(x)*g(x)\]\[(f/g)(x) = \frac{f(x)}{g(x)}\]

Answer 3

WAIT WHAT!??? Sorry it took a while for me to reply.
You gotta be kidding me. I did all of these questions wrong lol.

Answer 4

This is also precalculus lol chasingthepursuit :P