Question

2. A triangular pyramid begins with these coordinates:

Answer 1

1. The yz-plane is the plane x = 0. 
So, The general rule of reflection over the yz- plane is (x,y,z) →(−x,y,z)

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2. Applying the rule found in (1)

the new points of the shape after this reflection will be

P(–1, 2, 0)  ⇒⇒⇒ P'(1, 2, 0)
Y(2, 3, 0)    ⇒⇒⇒ Y'(-2, 3, 0)
R(–3, 4, 0)  ⇒⇒⇒ R'(3, 4, 0)
A(–2, 1, 5)  ⇒⇒⇒ A'(2, 1, 5)
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3. Applying the transformation rule (x, y, z) → (x + 2, y + 4, z – 3)

to the points from number 2

P'(1, 2, 0)  ⇒⇒⇒ P" (3 , 6 , -3 )
Y'(-2, 3, 0) ⇒⇒⇒ Y" (0 , 7 , -3)
R'(3, 4, 0)  ⇒⇒⇒ R" ( 5 , 8 , -3)
A'(2, 1, 5)  ⇒⇒⇒ A" ( 4 , 5 , 2)