Question

5. Use the functions to answer the question.

f(x) = 4x – 1; g(x) = 5x^2

Which is equal to (f circle g) (x)? (Points : 4)
80x^2 – 40x + 5
20x^3 – 5x^2
5x^2 + 4x – 1
20x^2 – 1

Answer 1

\[f\circ g(x)\] means
\[f(g(x))\]

Answer 2

step one is to write
\[f\circ g(x)=f(g(x))=f(5x^2)\]

Answer 3

then since
\[f(\diamondsuit)=4\diamondsuit -1\] you have
\[f(5x^2)=4\times 5x^2-1\]