Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫  π  -¹ ² ³ °

You are not logged in.

## #1 2018-03-31 02:29:17

Monox D. I-Fly
Member
From: Indonesia
Registered: 2015-12-02
Posts: 1,379

### [ASK] Reflection of a Line by Another Line

The reflection of the line 5x - 7y - 13 = 0 by the line y = -x is ....
A. 7x + 5y - 13 = 0
B. 7x + 5y + 13 = 0
C. 7x - 5y - 13 = 0
D. 7x - 5y + 13 = 0
E. 7y + 5x + 13 = 0

This one I totally have no idea. Like, at all.

Actually I never watch Star Wars and not interested in it anyway, but I choose a Yoda card as my avatar in honor of our great friend bobbym who has passed away. May his adventurous soul rest in peace at heaven.

Offline

## #2 2018-03-31 06:05:20

bob bundy
Registered: 2010-06-20
Posts: 8,462

### Re: [ASK] Reflection of a Line by Another Line

If you sketch the axes and the line of reflection you see that reflected points switch their x and y coordinates and reverse the signs eg (3,-4) becomes (4,-3)

Bob

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob Bundy

Offline