The problem tells by what factor and direction the graph of the given function is to be stretched or compressed. Give an
equation for the stretched or compressed graph.
-$y = \sqrt { x + 1 } \quad$ compressed vertically by a factor of 7
A) $y = \frac { \sqrt { x + 1 } } { 7 }$
B) $y = 7 \sqrt { x + 1 }$
C) $y = \sqrt { 7 x + 7 }$
D) $y = \sqrt { 7 x + 1 }$

Question

Quizplus · Accepted Answer

When a function is compressed vertically by a factor of $a$, it becomes $\frac{1}{a}$ times the original function. Thus, the equation for the compressed graph is $y=\frac{1}{7}\sqrt{x+1}$, or equivalently, $y=\frac{\sqrt{x+1}}{7}$. Out of the answer choices, only A matches this equation, so it is the correct choice.

The Problem Tells by What Factor and Direction the Graph y=x+1y = \sqrt { x + 1 } \quady=x+1​

The Problem Tells by What Factor and Direction the Graph $y = \sqrt { x + 1 } \quad$