Alexander Said:

In my wonderful world of graphs and equations, there is a disturbance... can someone lend me a hand?

We Answered:

It just means transform it into the form

(x - a)^2 + (y - b)^2 = r^2

where (a, b) arw the coordinates of the centre of the circle, and r its radius. First step is to simplify and rearrange the given equation

4.x^2 + 4.y^2 + 8.x - 16.y - 44 = 0

Every term is divisible by 4, so divide through by it; also group the x and y terms together

x^2 + 2.x + y^2 - 4.y = 11

Complete the squares for x and y separately, remembering to add the constant terms onto the right-hand side also

(x + 1)^2 + (y - 2)^2 = 11 + 1 + 4 = 16

so the centre of the circle is at (-1, 2) with a radius r of sqrt(16) = 4.

(Sorry, I'm a very slow typist!)

Cory Said:

Alqebra 2 homework help, please?

We Answered:

every straight line has an equation that can be written in the form y = mx + b
note the powers of x and y are both 1

every parabola will have an equation that can be written in the form y =- ax^2 + bx + c
note the powers of x and y..... one is 1 and the other is 2
don't worry if there is no bx or c terms


every circle can be written as x^2 + y^2 = r^2
note the powers of x and y..........both squared





"There are two ways to do great mathematics. The first is to be smarter than everybody else. The second way is to be stupider than everybody else -- but persistent." -- Raoul Bott

Velma Said:

How do I change the graph f'(x) to f(x)...?

We Answered:

As long as the dot is filled in, it's continuous (assuming the graph on both sides of 2 meet at that dot). But if its a sharp corner, it's not differentiable there, and it sounds like there would be a sharp corner. So pick b

Fernando Said:

How to graph circles?

We Answered:

It is much easier showing this in person than it is explaining on Yahoo Answers, but here goes.

To graph a circle, draw a point at the center. From the center, go straight up the number of units specified by the radius and draw another point. From the center, go straight down the number of units specified by the radius and draw another point. Do the same, going right and left the number of units specified by the radius and draw points.

You should now have five points on your graph, in the shape of a "+" sign. If you have a compass, use that to fill in the points on the circle. If you don't have a compass, then free-hand the circle, making sure it passes through the four points and is reasonably round.

To draw in the y-axis, use your ruler to draw a line through the center and the point above and below it. To draw in the x-axis, draw a line through the center and the points to its left and right. Make sure that both these lines extend beyond your circle, and draw arrows at the end to show that they continue on. Label your x-axis and y-axis somewhere outside the circle. At the center point, put a label, (x,y) with the x and y coordinates of the center.

The formula for a circle is (x - cx)^2 + (y - cy)^2 = r^2, if the center is at (cx, cy). You simply plug in your values for the center and the radius.

Dawn Said:

answer asap please 10 points for the best?

We Answered:

you should not depend on yahoo answers to do your home work

Alfredo Said:

algebra II: x^2-24y=0 (parabola) and x^2+y^2=25 (circle I think)?

We Answered:

x^2-24y=0 => y = (1/24)*x^2 (parabola)
x^2+y^2=25 is a circle

George Said:

Percentage problem, please help?

We Answered:

So you add them all up and you get 300. Now divide the Basketball (75) by 300 and you get 75/300 = .25 or 25%.
Do the same with the hockey. 30/300 = 0.1 or 10%.
The percent difference is the difference between the two, or 25% - 10% = 15%.