Question

1. error analysis oscar drew the image of a triangle reflected across the line y = -1. what mistake did oscar make? enter your answer. check answer

Explanation:

Step1: Recall reflection rule

When reflecting a point $(x,y)$ across the line $y = k$, the rule is $(x,2k - y)$. Here $k=-1$, so the rule is $(x,- 2 - y)$.

Step2: Analyze Oscar's work

Oscar likely used the wrong - axis or wrong rule. He may have thought it was a reflection across the $x$ - axis (where the rule is $(x,-y)$) or made an error in calculating the distance from the line $y = - 1$. For a point $(x,y)$ in the pre - image, its distance to the line $y=-1$ is $d=y + 1$. The $y$ - coordinate of the reflected point should be $-1-(y + 1)=-y - 2$. But it seems Oscar did not calculate this distance correctly.

Answer:

Oscar did not calculate the correct $y$ - coordinates of the reflected points using the rule for reflection across the line $y=-1$. He likely used an incorrect reflection rule, perhaps thinking it was a reflection across the $x$ - axis.