chris wanted to transform the graph of the parent function (y = cot(x)) by horizontally compressing it so…

chris wanted to transform the graph of the parent function (y = cot(x)) by horizontally compressing it so that it has a period of (\frac{pi}{2}) units, horizontally translating it (\frac{pi}{4}) units to the right, and vertically translating it 1 unit up. to do so, he graphed the function (y=cot(2x - \frac{pi}{4})+1), as shown. what did he do wrong?

chris wanted to transform the graph of the parent function (y = cot(x)) by horizontally compressing it so that it has a period of (\frac{pi}{2}) units, horizontally translating it (\frac{pi}{4}) units to the right, and vertically translating it 1 unit up. to do so, he graphed the function (y=cot(2x - \frac{pi}{4})+1), as shown. what did he do wrong?

Answer

Answer:

He made a mistake in the horizontal - translation part. The correct function for the given transformations should be (y = \cot\left(2\left(x-\frac{\pi}{4}\right)\right)+1=\cot\left(2x - \frac{\pi}{2}\right)+1), not (y=\cot\left(2x-\frac{\pi}{4}\right)+1).

Explanation:

Step1: Recall transformation rules

For (y = f(x)), horizontal compression by a factor (a) gives (y = f(ax)), horizontal translation (h) units to the right gives (y=f(x - h)) and vertical translation (k) units up gives (y=f(x)+k).

Step2: Analyze horizontal compression

The parent function is (y = \cot(x)). Horizontal compression to have a period of (\frac{\pi}{2}) (since the period of (y=\cot(x)) is (\pi) and for (y = \cot(bx)) the period is (\frac{\pi}{|b|}), so (b = 2) for period (\frac{\pi}{2})) gives (y=\cot(2x)).

Step3: Analyze horizontal translation

After horizontal compression, to translate (\frac{\pi}{4}) units to the right, we replace (x) with ((x - \frac{\pi}{4})) in (y=\cot(2x)). So the function should be (y=\cot\left(2\left(x-\frac{\pi}{4}\right)\right)=\cot\left(2x-\frac{\pi}{2}\right)).

Step4: Analyze vertical translation

Finally, vertical translation 1 unit up gives (y=\cot\left(2x - \frac{\pi}{2}\right)+1). So the error is in the horizontal - translation part of the function Chris wrote.