by DaleCallahan | Feb 8, 2017 | Blog
Where did all these formulas come from anyway? Here’s some interesting information on the Quadratic Equation. All forms of math and science (including cooking, shopping, etc) are loaded with formulas. Formulas are nothing but a relationship between two different...
by DaleCallahan | Feb 8, 2017 | Blog
Grab a copy of the model rocket activity here. This activity is suitable for any of the math courses or Algebra, Geometry, Algebra 2 with Trig, or Calculus. Note: We are talking about model rockets, which since they stay under the forces of the earth’s gravity,...
by DaleCallahan | Jan 14, 2017 | Algebra 2 wTrig Chapter 6, Algebra II with Trig
The quick hint is this… label the bottom length x so that the entire bottom section of the RIGHT triangle is d+x. Then you can say tan(ALPHA) = h / (x+d) tan (BETA) = h/x then solve the second for x and substitute into the first. For details, you can see the...
by DaleCallahan | Jun 28, 2016 | General High School Questions
The U.S. schools are weak in math – almost all of them regardless of public, private, or homeschool. The national weakness in math (and science – which is related) is a growing problem. Math and science are required for all STEM (Science, Technology,...
by DaleCallahan | May 10, 2016 | Calculus, Calculus Tests
Beverly asked: Looks like you have a simplification error in the second derivative. You have: f”(x)=12x^2-4=4(x-1) But it should be f”(x)=12x^2-4=4(3x^2-1) then the intervals for concavity all change. Am I missing something? Thank you so much for your good...
by DaleCallahan | Apr 23, 2016 | Calculus, Calculus Tests
Question from Beverly: #3 – on the test copy I have says to use three equal subintervals. But in the handwritten solution, it appears that they used 6. If the student uses 3 subintervals wouldn’t the ∆X be 2 and the right endpoint sum be 0.2, left end...
by DaleCallahan | Apr 4, 2016 | Geometry, Geometry Chapter 14, Geometry Tests
Question: how do we work the problem on Chapter 14 test #4. Answer from Harold Jacobs: Since all 16 white regions are identical, we can find the area of one of them and multiply it by 16. This figure represents one of the 16 small squares and one of the white regions....
by DaleCallahan | Feb 26, 2016 | Geometry, Geometry Chapter 10, Known Geometry Errors
Kerry Asked: In Chp. 10, Lesson 4, Set III Question 4 the textbook asks “Why is QD/AC = DB/CD?” Shouldn’t it be DB/CB instead of DB/CD? Dr. Callahan Answered: Again you are correct. This is an error in the new printing of the 3rd edition by My...
