ACT Math 4.2 Trigonometry
ACT Math: Trigonometry; Drill 4, Problem 2. Which equation matches this graph?
|Foreign Language||Arabic Subtitled|
|Geometry||Right Triangles and Trigonometry|
|Product Type||ACT Math|
The bottom part of the graph only seems to go down to negative 1, while
the top parts reach all the way up to positive 3.
A normal cosine graph goes up and down in even amounts relative to the x-axis, which
means that this one is lifted up by 1...
...in other words, if we bring the graph down by 1, it will reach both 2 and negative 2.
The "lift" is represented by a "plus 1" which leaves only
answer choices D and E in the running.
place that pesky 2 -- before or inside of the parentheses?
We know that anything inside the parentheses modifies the period of the graph, or how tightly
the waves of the graph cycle. A normal cosine graph completes a full cycle
in 2π, and our cosine graph does the same, so it was not modified.
That means the 2 can't be in the parentheses but rather before the cos -- answer E.