select the correct answer. which two points have an undefined slope? a. (-1,1) and (1,-1) b. (-2,2) and…

select the correct answer. which two points have an undefined slope? a. (-1,1) and (1,-1) b. (-2,2) and (2,2) c. (-3,-3) and (-3,3) d. (-4,-4) and (4,4)
Answer
Explanation:
Step1: Recall slope formula
The slope $m$ between two points $(x_1,y_1)$ and $(x_2,y_2)$ is $m=\frac{y_2 - y_1}{x_2 - x_1}$. The slope is undefined when $x_2 - x_1=0$.
Step2: Check each option
Option A
For points $(-1,1)$ and $(1, - 1)$, $x_1=-1,x_2 = 1$, $x_2 - x_1=1-(-1)=2\neq0$.
Option B
For points $(-2,2)$ and $(2,2)$, $x_1=-2,x_2 = 2$, $x_2 - x_1=2-(-2)=4\neq0$.
Option C
For points $(-3,-3)$ and $(-3,3)$, $x_1=-3,x_2=-3$, $x_2 - x_1=-3-(-3)=0$.
Option D
For points $(-4,-4)$ and $(4,4)$, $x_1=-4,x_2 = 4$, $x_2 - x_1=4-(-4)=8\neq0$.
Answer:
C. $(-3,-3)$ and $(-3,3)$