MathLab with Mr. Ahmed is a math learning website by Ahmed Amasha, a mathematics teacher teaching the American curriculum. Explore Algebra 2, Precalculus, Calculus, and SAT and PSAT Math Prep through lessons, focused practice and printable resources.
In a2(x−h)2+b2(y−k)2=1, the ellipse center is (h,k).
Worked example 1
01 / Find the center of 9(x−4)2+25(y+7)2=1.
02 / Match (x−h) and (y−k): the center is (4,−7).
03 / Answer: (4,−7)
Worked example 2 · Shifted circle radius
Find the radius of (x−4)2+(y+6)2=64.
The radius is the positive square root of 64. Answer: 8
15 questions covering every idea, with a worked answer for each.Start practice ↗
Textbook reference: Stewart, Redlin & Watson, Precalculus: Mathematics for Calculus, 7th ed. (Cengage, 2016). The explanations and practice here are original, organized by textbook section.