Answer: a = -3
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Work Shown:
The point (1, -3) is on the blue graph p(x) = a|x|
This means x = 1 and y = -3 pair up.
Use these two values to find 'a'
p(x) = a|x|
y = a|x|
-3 = a*|1|
-3 = a*1
-3 = a
a = -3
The negative 'a' value will apply the reflection over the x axis. The fact that |a| = 3 is larger than 1 indicates the graph is vertically stretched by a factor of 3.