Question

A ray of light is reflected off a mirror such that the reflected ray is perpendicular to the original ray, as shown in the diagram. What is the equation of the reflected ray?

Answer 1

@Luigi0210 Could you help me on this?

Answer 2

@DullJackel09 Will you help me, if you can?

Answer 3

Idk this sorry

Answer 4

Its all good thank you anyways.

Answer 5

@ganeshie8 Would you be willing to help me.

Answer 6

@undeadknight26 would you help me?

Answer 7

Okay, since you know that the rays are perpindicular we know that there is a 90 degree angle between them right? And since there are a total of 180 degrees in the plane it reflected off of we have 180 - 90 = 90 right? Now, we know that the angle of incidence is equal to the angle of reflection so since those two angles are equal and we have 90 degrees left we have 90 / 2 = 45 degrees. That should help get you started?

Answer 8

(A) y-x=6, (B) y+x=6, (C) -y+x=6, (D) y+x=5, (E) y-x=5

Answer 9

So you know it has the same intercept right? A perpindicular line will have the inverse recipirocal slope of its counterpart line

Answer 10

Yes i think knew that.

Answer 11

Still not completely sure on what to do with the information you've given me.

Answer 12

So what is the slope of the original line?

Answer 13

and what is the intercept of the original line?

Answer 14

The slope and intercept of y-x=4?

Answer 15

yep

Answer 16

Slope = +1, y-intercept=+4.

So find the slope and the y-intercept of the perpendicular to this line.

Answer 17

Or just give him the answer, sure

Answer 18

To be honest i don't know where to plug those in.

Answer 19

Okay so what is the inverse recipirocal of 1? Since the inverse recipirocal of the slope of the first line will give us a line perpindicular to it

Answer 20

-1?

Answer 21

You got it! Nice! So from the picture we can see they have the same intercept right?

Answer 22

Yes.

Answer 23

So what do you think the equation is then?

Answer 24

Well i think its (c) because of the negative y, you said it was the inverse of the y intercept.

Answer 25

Not quite. In c the intercept is 6. When we rearrange we get y = x - 6. Try again

Answer 26

Our intercept is 5 and our slope is -1

Answer 27

So it would be (E) then, because it has a intercept is 5 and a slope of -1

Answer 28

@azolotor

Answer 29

Close but not quite. Solve that equation for y and see what the slope is.

Answer 30

How do i solve for y?

Answer 31

Its (D).

Answer 32

Great job!