Sketch Reflections of Functions
# Sketch Reflections of Functions

GCSE(H)

Graphs can be reflected by applying negative values to a function.

If the negative value is applied *before* the function takes place, then the result is a reflection in the *y*-axis:

`y=f(-x)` will reflect the function `y=f(x)` in the *y*-axis.

If the negative value is applied to the *result* of the function, then the reflection will take place in the *x*-axis:

`y=-f(x)` will reflect the function `y=f(x)` in the `x`-axis.

## Examples

1. Sketch the graph of the function `f(x)=3x+4`. On the same graph, sketch `f(-x)`. Label the graph.

Answer:

2. A function is given by `f(x)=3sin(x)`. The function returns a value of -3 when `x=270ยบ`. Sketch the graph for `f(-x)` where 0 < *x* < 360.

Answer:

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