Math Is Fun Forum

mathxyz

Member

From: Brooklyn, NY

Registered: 2024-02-24

Posts: 1,053

Find All Points

Problem 48; page 7
Precalculus book.

Find all points having a y-coordinate of -6 whose distance from the point (1, 2) is 17.

A. By using the Pythygorean Theorem.

B. By using the distance formula.

When it comes to problems that I don't know how to solve, I always request the first-two steps.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,524

Re: Find All Points

This question is on page 41 in my copy of the book.  Mine has pages of introductions before the first lessons and questions.  41-7 = 34. Maybe I'll have to apply a transformation of (my page = (your page) + 34 to find the questions.

The distance formula comes directly from Pythagoras' theorem, so I would end up with the same equation using either.

Let the point be (x,-6)

(x-1)^2 + (-6-2)^2 = 17^2

Solve for x, two solutions.

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

mathxyz

Member

From: Brooklyn, NY

Registered: 2024-02-24

Posts: 1,053

Re: Find All Points

This question is on page 41 in my copy of the book.  Mine has pages of introductions before the first lessons and questions.  41-7 = 34. Maybe I'll have to apply a transformation of (my page = (your page) + 34 to find the questions.

The distance formula comes directly from Pythagoras' theorem, so I would end up with the same equation using either.

Let the point be (x,-6)

(x-1)^2 + (-6-2)^2 = 17^2

Solve for x, two solutions.

Bob

Do you have Edition 10 of the book? I you have another edition, the problems are located on different pages. In Edition 10, the problem is on page 7. I will work this out on paper. No more math for the rest of the week.