Question

Triangle XYZ is reflected about the y-axis. What are the coordinates of X’?

Answer 1

Just flip the signs of co-ordinates by using formula y=>-y

• Make sure to do this with y only as it has been reflected to y axis

$\\ \ast\bull\rm\longmapsto Z(-5,-4)\implies Z'=(-5,-(-4))\implies Z'=(-5,4)$

$\\ \ast\bull\rm\longmapsto Y(-3,-4)\implies Y'=(-3,-(-4))\implies Y'=(-3,4)$

$\\ \ast\bull\rm\longmapsto X(-5,-1)\implies X'=(-5,-(-1))\implies X'=(-5,1)$

Answer 2

Answer:

• Reflection about the x-axis, consider a point A

${ \tt{A(x,y) \: \dashrightarrow \:A {}^{i} ( - x, \: y) }}$

• Therefire, coordinates of X'

$\dashrightarrow \: { \boxed{ \tt{X( - 5, \: - 1) = X'(5, \: - 1)}}}$