Question

F(x)= -5x+9 ; reflection in the y-axis a.g(x)=5x-9 b.g(x)=5x+9 c.g(x)=9x-5 d.g(x)=5x-5

Answer 1

Answer: g(x) = 5x+9, second choice

Explanation:

When we reflect over the vertical y axis, every negative x value becomes positive and vice versa. So we effectively replace x with -x like so

f(x) = -5x+9

f(-x) = -5(-x)+9 ... replace every x with -x

f(-x) = 5x+9

g(x) = 5x+9

A point like (1,4) on f(x) will reflect over to (-1,4) on g(x). If we apply this to every point on f(x), then all of f(x) will reflect to g(x).