Question

Given f(x)=2x^2-1 and g(x)=7-1/2x^2, find the following expressions.

a.(f•g) (4)
b.(g•f) (2)
c.(f•f) (1)
d.(g•g) (0)

Answer 1

do the dots mean composite or multiplication? it's hard to tell

Answer 2

multiplication

Answer 3

I'll help you do (A)
\[f(x)=2x^2-1\]\[g(x)=7-\frac{1}{2x^2}\]
Now, you want to find:\[4(f*g)\]
Simply sub the values from before into it
\[4((2x^2-1)(7-\frac{1}{2x^2}))\]
\[\frac{4}{1}((\frac{2x^2-1}{1})(\frac{7}{1}-\frac{1}{2x^2}))\]
Multiply the section with \(2x^2\)
\[\frac{4}{1}*\frac{2x^2}{2x^2}((\frac{2x^2-1}{1}*\frac{2x^2}{2x^2})(\frac{7}{1}*\frac{2x^2}{2x^2}-\frac{1}{2x^2}))\]
\[\frac{8x^2}{2x^2}((\frac{4x^4}{2x^2})(\frac{7x^2}{2x^2}-\frac{1}{2x^2}))\]
\[8x^2((4x^4)(7x^2-1))\]
You can go from there