katrinahednerso katrinahednerso
  • 07-07-2016
  • Mathematics
contestada

The point (2, –4) is reflected across the line y = –1. What are the coordinates of the image?
A.(–5, –4)
B.(–4, 2)
C.(2, 2)
D.(2, 4)

Respuesta :

mathmate
mathmate mathmate
  • 07-07-2016
Hint:
r_{y=k): (x,y)->(x,-(y-k)+k)
or simplified,
r_{y=k): (x,y)->(x,2k-y)

So in this case, k=-1, x=2, y=-4
(2,-4) -> (2, 2(-1)-(-4)
(2,-4) -> (2, -2+4)
(2,-4) -> (2, 2)
Answer Link

Otras preguntas

Using the digits 3, 4, 7, and 8, write the largest possible number in word form, if 3 is in the hundreds place
how can you use a number line to help you understand the size of the number 13,700?
What is the value of the 8 in 2,008,277
calculate the sum of 6.078 g and 0.3329 g
During a discussion in science class, Sharon learns that at birth an elephant weighs around 230 pounds. In fourth herds of elephants tracked by conversationists
suppose that you have 10 coins consisting of quarters and dimes. if you have a total of $1.90, find the number of each type of coin.
Which of these lines contains the clearest example of dialect in poetry?
What are the two sources of heat in the earths interior?
Which of the following is not categorized as a high performance Asian economy
how are school rules similar to the us government