**Sunday, October 14th, 2018**:
We have a new activity, called

Volume of Cones, Pyramids, Cylinders, and Spheres. This MATHguide activity addresses Common Core State Standards for 9th grade mathematics (geometry): HSG.GMD.A.3.

**Saturday, October 13th, 2018**:

We have a new activity, called Real-World Circular Volume Problems. This MATHguide activity addresses Common Core State Standards for 8th grade mathematics (geometry): 8.G.C.9.

**Monday, October 8th, 2018**:

We have a new interactive quizmaster, called Rational Expressions: Asymptotes and Holes.

**Saturday, August 4th, 2018**:

We have a new instructional calculus video, called Related Rates: Ladder Problem.

**Wednesday, August 2nd, 2018**:

We have a new instructional calculus video, called Deriving the Derivative of the Cosine Function.

**Wednesday, August 1st, 2018**:

We have a new instructional calculus video, called Deriving the Derivative of the Sine Function.

**Tuesday, July 31st, 2018**:

We have a new instructional calculus video, called Approximating the Area Under a Curve: Trapezoids.

**Monday, July 30th, 2018**:

We have a new instructional calculus video, called Approximating the Area Under a Curve: Right Rectangles.

**Friday, July 27th, 2018**:

We have a new instructional calculus video, called Approximating the Area Under a Curve: Left Rectangles.

**Thursday, July 26th, 2018**:

We have a new instructional calculus video, called Approximating the Area Under a Curve.

**Monday, July 23rd, 2018**:

We have a new instructional calculus video, called Derivatives: Chain Rule Examples.

**Sunday, July 22nd, 2018**:

We have a new instructional calculus video, called Derivatives: Quotient Rule Examples.

**Saturday, July 21st, 2018**:

We have three new instructional calculus videos:

**Monday, July 9th, 2018**:

We have a new instructional calculus video, called Derivatives: Deriving the Quotient Rule.

**Sunday, July 8th, 2018**:

We have a new instructional calculus video, called Derivatives: Radical Functions.

**Saturday, July 7th, 2018**:

We have two new instructional calculus videos, called:

**Friday, July 6th, 2018**:

We have a new instructional calculus video, called Derivatives: Deriving the Sum Rule.

**Thursday, July 5th, 2018**:

We have a new instructional calculus video, called Derivatives: Polynomials.

**Wednesday, July 4th, 2018**:

Happy 4th of July -- Independence Day!

We have a new instructional calculus video, called Derivatives: Derivation and Explanation. A new section was created for calculus content on our lesson page.

**Tuesday, July 3rd, 2018**:

We have a new service, called Advanced High School Math Standards. It is the third level of three levels within our suggested framework for mathematics standards.

**Monday, July 2nd, 2018**:

We have a new instructional video, called Simplifying Trigonometric Expressions: Common Denominator.

**Thursday, June 21st, 2018**:

We have a new service, called Proficient High School Math Standards. It is the second level of three levels within our suggested framework for mathematics standards.

**Thursday, June 14th, 2018**:

We have a new interactive quiz, called Rational Expressions: Asymptotes.

**Wednesday, June 13th, 2018**:

We have two new instructional videos, called:

**Saturday, June 9th, 2018**:

We have a new instructional video, called Graphing Rational Expressions as Transformations.

**Wednesday, June 6th, 2018**:

We have a new lesson, called Solving Complicated Proportions.

**Tuesday, June 5th, 2018**:

We have a new...

**Friday, June 1st, 2018**:

We have a new...

**Friday, May 25th, 2018**:

We have a new lesson, called Polar Coordinates.

**Tuesday, May 22nd, 2018**:

We have a new instructional video, called Polar Equations to Rectangular Equations.

**Monday, May 21st, 2018**:

We have a new instructional video, called Rectangular Equations to Polar Equations.

**Sunday, May 13th, 2018**:

We have a new instructional video, called Polar Coordinates and Rectangular Conversions.

**Monday, April 30th, 2018**:

We have a new instructional video, called Similar Figures: Ratios of Lengths and Areas.

**Sunday, April 29th, 2018**:

We have a new instructional video, called Similar Solids: Ratios of Lengths and Volumes.

**Tuesday, April 24th, 2018**:

We have a new instructional video, called Negative Angle Identity Proofs.

**Monday, April 23rd, 2018**:

We have a new instructional video, called Negative Angle Identities.

**Friday, April 6th, 2018**:

We have a new instructional video, called Limits of Piecewise Functions.

**Wednesday, April 4th, 2018**:

We have two new instructional videos...

**Saturday, March 31st, 2018**:

We have a new instructional video, called Lines and Segments: Parallel, Perpendicular, Neither.

**Wednesday, March 28th, 2018**:

We have a new instructional video, called Calculating the Angle Between Vectors.

**Tuesday, March 27th, 2018**:

We have a new instructional video, called Surface Area of a Rectangular Prism.

**Saturday, March 24th, 2018**:

We have a new quiz, called Parallel, Perpendicular, or Neither.

**Wednesday, March 21st, 2018**:

We have a new lesson, called Margin of Error and Confidence Intervals by Formula.

**Tuesday, March 20th, 2018**:

We have a new lesson, called Margin of Error and Confidence Intervals.

**Saturday, March 19th, 2018**:

We have a new quiz, called Classifying Triangles Using Slope & Distance.

**Sunday, March 18th, 2018**:

We have two new lessons:

**Saturday, March 17th, 2018**:

We have a new quiz, called Classifying Parallelograms Using Slope and Distance.

**Tuesday, March 13th, 2018**:

We have a new quiz, called Classifying Parallelograms Using Slope.

**Saturday, March 10th, 2018**:

We have a new quiz, called Mean, Standard Deviation, and Margin of Error.

**Thursday, March 8th, 2018**:

We have a new lesson, called Bell Curve: 68-95-99 Rule.

**Sunday, March 4th, 2018**:

We have a new lesson, called Standard Deviation.

**Monday, February 26th, 2018**:

We have a new quiz, called Confidence Intervals Using a Formula.

**Monday, February 26th, 2018**:

We have a new quiz, called Margin of Error from Confidence Interval.

**Sunday, February 25th, 2018**:

We have two new updates:

**Saturday, February 24th, 2018**:

We have two new quizzes:

**Thursday, February 22nd, 2018**:

We have a new quiz, called Bell Curve: Standard Deviation.

**Tuesday, February 20th, 2018**:

We have a new instructional video, called Confidence Intervals and Margin of Error: TI-Nspire.

**Sunday, February 19th, 2018**:

We have a new lesson, called Half Angle Formulas (Sine, Cosine).

**Tuesday, February 13th, 2018**:

We have a new quiz, called Dice Roller: Mean and Standard Deviation.

**Sunday, February 11th, 2018**:

We have two new updates:

**Saturday, February 10th, 2018**:

We have a new lesson, called Double Angle Formulas (Sine, Cosine, Tangent).

**Friday, February 9th, 2018**:

We have a new lesson, called Sum & Difference Angle Formulas (Tangent).

**Sunday, February 4th, 2018**:

We have a new lesson, called Sum & Difference Angle Formulas (Sine, Cosine).

**Saturday, February 3rd, 2018**:

We have a new instructional video, called Sum and Difference Angle Formulas. We also have a new interactive quizmaster, called Sum and Difference Angle Formulas.

**Monday, January 29th, 2018**:

We have a new lesson, called Properties of Rectangles.

**Saturday, January 27th, 2018**:

We have a new lesson, called Properties of Parallelograms.

**Sunday, January 21st, 2018**:

We have a new lesson, called Properties of Quadrilaterals.

**Thursday, January 18th, 2018**:

We have a new service, called Conversion: Temperature.

**Wednesday, January 17th, 2018**:

We have a new quiz, called Properties of Quadrilaterals.

**Monday, January 15th, 2018**:

We have a new service, called Conversion: Volume.

**Sunday, January 14th, 2018**:

We have a new service. It is a calculator that converts between area units. It is called Conversion: Area.

**Monday, January 8th, 2018**:

We have a new service. It is a calculator that converts between velocity units. It is called Conversion: Velocity.