Question

Check my answer? Identifying reflections?

Identify a reflection about the x-axis or a reflection about the y-axis of ƒ(x) = x^2 + 4x^3 by observing the equation of the function g(x) = x^2 – 4x^3.

(A) A reflection about the x-axis
(B) A rreflection about the y-axis

I think the answer is B, a reflection about the y axis, can anyone confirm?

Answer 1

f(-x) is a reflection of f(x) about the y axis

-f(x) is a reflection of f about the x axis

Answer 2

yes

Answer 3

so my answer is right then @perl ?

Answer 4

Also explain why you think B is the answer

Answer 5

4x^3 seems like it would result in a lower number than x^2, and the lower the number means it will travel left across the coordinate grid across the y axis

Answer 6

you seem to be having right intuition, but this can be worked more efficiently. look at perl's reply

Answer 7

I'll remember perl's method but is my answer correct?

Answer 8

f(x) = x^2 + 4x^3

f(-x) = ?

Answer 9

x^2 - 4x^3

Answer 10

f(-x) = x^2-4x^3 = g(x)

so yeah g(x) is the reflection of f(x) about the y-axis

Answer 11

thank you

Answer 12

you're welcome!

Answer 13

b