Let \(f(x)=2x^2-3x+4\) and \(g(x)=x+1\). Find the correct expression for evaluating \(g(f(5))\).

a) \((2(5+1)^2-3(5+1) +4) +1\)

b) \((2(5)^2-3(5)+4)+1\)

c) \((2(5+1)^2-3(5+1)+4)\)

d) \((2(5-1)^2-3(5-1)+4)+1\)

SmartMathMan Jan 17, 2021

#1**+3 **

just replace the x in the g function with 2x^2-3x+4

and then sub 5 for x.

**You tell us what you get. **

Melody Jan 17, 2021

#2**+2 **

That gave me the same answer I already came up with.

\(g(f(5))=2(5)^2-3(5)+4+1\)

I was shown how to get here but I don't know how to write the expression the way they want it.

Is the answer b) ? What I got looks similar to it.

SmartMathMan
Jan 18, 2021

#3**0 **

what you have written is exactly the same as B. No need to rearrange anything.

B just has one added set of brackets but they do not change the value at all.

Melody Jan 18, 2021

#5**+1 **

Thank you! I'll definitely check the link out. I could use some extra practice in this area.

SmartMathMan
Jan 19, 2021