|
Lecture

# Foci of an Ellipse

Home > Mathematics > Algebra > Foci of an EllipseLecture Details:

Calculating the foci (or focuses) of an Ellipse.

Lectures:
• ### Simple Equations

00:11:06Salman Khan

Introduction to basic algebraic equations of the form Ax=B.

• ### Equations Part 2

00:08:41Salman Khan

Slightly more complicated equations.

• ### Equations Part 3

00:08:53Salman Khan

Equations with the variable on both sides.

• ### Linear Equations

00:07:38Salman Khan

Solving linear equations with variable expressions in the denominators of fractions.

• ### Graphing Lines Part 1

00:09:49Salman Khan

Graphing linear equations.

• ### Slope and Y-intercept Intuition

00:08:35Salman Khan

Getting a feel for slope and y-intercept.

• ### Slope Part 1

00:08:27Salman Khan

Figuring out the slope of a line.

• ### Slope Part 2

00:09:46Salman Khan

Second part of determining the slope of a line.

• ### Slope Part 3

00:06:21Salman Khan

Part 3 of slope.

• ### Averages

00:08:36Salman Khan

Introduction to averages and algebra problems involving averages.

• ### Integer Sums

00:09:55Salman Khan

• ### Taking Percentages

00:09:54Salman Khan

Taking a percentage of a number.

• ### Growing by a Percentage

00:09:42Salman Khan

Growing a quantity by a percentage.

• ### Another Percent Word Problem

00:06:18Salman Khan

Finding the full price when you know the discount price.

• ### More Percent Problems

00:09:05Salman Khan

Slightly harder percent problems.

• ### Systems of Equations

00:09:57Salman Khan

Systems of equations.

• ### Ratio Problem with Basic Algebra

00:05:12Salman Khan

A slightly more involved ratio problem with algebra.

00:09:58Salman Khan

More advance ratio problem with algebra.

• ### Alternate Solution to Ratio Problem

00:07:02Salman Khan

An alternate solution to the advanced ratio problem in the last video.

• ### Introduction to Ratios

00:07:27Salman Khan

Basic ratio problems.

00:09:57Salman Khan

• ### Age Word Problems Part 1

00:07:12Salman Khan

Age word problems.

• ### Age Word Problems Part 2

00:09:56Salman Khan

Second set of age word problems.

• ### Age Word Problems Part 3

00:04:08Salman Khan

Part 3 of the presentation on age word problems.

• ### Level 1 Multiplying Expressions

00:07:58Salman Khan

(Ax+By)(Ax+By).

• ### Solving a Quadratic by Factoring

00:09:12Salman Khan

• ### i and Imaginary Numbers

00:09:17Salman Khan

Introduction to i. Raising i to arbitrary exponents.

• ### Complex Numbers Part 1

00:10:10Salman Khan

Introduction to complex numbers. Adding, subtracting and multiplying complex numbers.

• ### Complex Numbers Part 2

00:08:58Salman Khan

Dividing complex numbers. Complex conjugates.

• ### Introduction to the Quadratic Equation

00:09:15Salman Khan

Introduction to using the quadratic equation to solve 2nd degree polynomials.

• ### Quadratic Equation Part 2

00:09:14Salman Khan

2 more examples of solving equations using the quadratic equation.

• ### Completing the Square

00:13:45Salman Khan

Solving a quadratic by completing the square.

00:07:34Salman Khan

Deriving the quadratic formula by completing the square.

00:09:48Salman Khan

• ### Functions Part 1

00:09:32Salman Khan

An introduction to functions.

• ### Functions Part 2

00:09:53Salman Khan

More examples of solving function problems.

• ### Functions Part 3

00:09:12Salman Khan

Even more examples of function exercises. Introduction of a graph as definition of a function.

• ### Functions Part 4

00:06:07Salman Khan

An example of a functions problem submitted by a youtube viewer.

• ### Domain of a Function

00:09:59Salman Khan

Figuring out the domain of a function.

• ### Proof: log a + log b = log ab

00:07:08Salman Khan

Proof of the logarithm property: log a + log b = log ab.

• ### Proof: A(log B) = log (B^A), log A - log B = log (A/B)

00:07:57Salman Khan

Proofs of the logarithm properties: A(log B) = log (B^A) and log A - log B = log (A/B).

• ### Proof: log_a (B) = (log_x (B))/(log_x (A))

00:07:25Salman Khan

Proof of the logarithm property.

• ### Algebraic Long Division

00:10:21Salman Khan

Dividing one polynomial into another.

• ### Introduction to Conic Sections

00:10:58Salman Khan

What are conic sections and why are they called "conic sections"?

• ### Conic Sections: Circles

00:09:04Salman Khan

Introduction to the Circle.

• ### Conic Sections: Ellipses

00:14:14Salman Khan

Introduction to the ellipse.

• ### Conic Sections: Hyperbolas Part 1

00:13:34Salman Khan

Introduction to the hyperbola.

• ### Conic Sections: Hyperbolas Part 2

00:07:30Salman Khan

Continuation of the intro to hyperbolas.

• ### Conic Sections: Hyperbolas Part 3

00:10:29Salman Khan

Part 3 of the intro to hyperbolas.

• ### Identifying Conics Part 1

00:09:11Salman Khan

Part 1 of identifying and graphic conic sections.

• ### Identifying Conics Part 2

00:11:28Salman Khan

Part 2 of identifying and graphing conic sections.

• ### Identifying Conics Part 3

00:11:34Salman Khan

Let's identify (and graph) a couple of more conics!

• ### Foci of an Ellipse

00:13:49Salman Khan

Calculating the foci (or focuses) of an Ellipse.

• ### Foci of a Hyperbola

00:15:24Salman Khan

Introduction to the foci (focuses) of a hyperbola.

• ### Hyperbola Foci

00:14:50Salman Khan

Proof of the hyperbola foci formula.

• ### Partial Fraction Expansion Part 1

00:11:28Salman Khan

Introduction to partial fraction expansion.

• ### Partial Fraction Expansion Part 2

00:13:02Salman Khan

A more complex problem.

• ### Partial Fraction Expansion Part 3

00:10:35Salman Khan

Dealing with repeated factors.

• ### Parabola Focus and Directrix Part 1

00:14:31Salman Khan

Parabola as the locus of all points equidistant from a point and a line.

• ### Parabola Focus and Directrix Part 2

00:18:28Salman Khan

Finding the focus and directrix of a parabola.

• ### Two Passing Bicycles Word Problem

00:05:39Salman Khan

Algebra word problem involving two bicycles passing each other.

• ### Passed Bike Word Problem

00:05:54Salman Khan

Fun algebra word problem involving a train passing a bike.

• ### Passing Trains

00:09:07Salman Khan

Trains passing at different rates.

• ### Overtaking Word Problem

00:09:52Salman Khan

3 people overtaking each other at different rates.

• ### Early Train Word Problem

00:07:07Salman Khan

Fun word problem that is almost a brain teaser.

• ### Officer on Horseback

00:08:54Salman Khan

Not quite a brain teaser but fun nonetheless!

• ### Rational Inequalities Part 1

00:11:49Salman Khan

Two ways to solve a rational inequality (or an inequality involving a fractional expression).

• ### Rational Inequalities Part 2

00:13:15Salman Khan

Slightly harder rational inequality problem.

• ### Interesting Polynomial

00:16:15Salman Khan

Finding the coefficients of a third degree polynomial given 2 roots and the y-intercept.

• ### Geometric Series Sum to Figure Out Mortgage Payments

00:17:36Salman Khan

Figuring out the formula for fixed mortgage payments using the sum of a geometric series.