Mathematics Grade 10 15 min

Multiply by 3-digit numbers

Multiply by 3-digit numbers

Tutorial Preview

1

Introduction & Learning Objectives

Learning Objectives Accurately square any 3-digit number to find the value of r² for a circle's equation. Apply the distributive property to multiply binomials containing 3-digit numbers, such as (x - h)² where h is a 3-digit integer. Convert the standard form equation of a circle, (x - h)² + (y - k)² = r², into its general form, x² + y² + Dx + Ey + F = 0, when h, k, or r are 3-digit numbers. Calculate the coefficients D, E, and F for the general form of a circle's equation using multiplication with 3-digit numbers. Verify the accuracy of large-number calculations when manipulating circle equations. Determine the constant term F in the general form by combining multiple terms derived from squaring 3-digit numbers. Ever wondered how engineers model a massive radio t...
2

Key Concepts & Vocabulary

TermDefinitionExample Standard Form of a CircleThe equation (x - h)² + (y - k)² = r², which explicitly defines a circle with a center at the point (h, k) and a radius of length r.The equation (x - 110)² + (y - 50)² = 900 represents a circle centered at (110, 50) with a radius of 30 (since √900 = 30). General Form of a CircleThe equation x² + y² + Dx + Ey + F = 0, where D, E, and F are constants. This form is derived by expanding the standard form.x² + y² - 220x - 100y + 12200 = 0 is the general form of the circle from the previous example. Center (h, k)The central point from which all points on the circle are equidistant. In the standard form, these are the values being subtracted from x and y.For the circle (x - 125)² + (y + 200)² = 1, the center is (125, -200). Radius (r)The fixed dista...
3

Core Formulas

Standard Form to General Form Conversion (x - h)² + (y - k)² = r² expands to x² + y² - 2hx - 2ky + (h² + k² - r²) = 0 Use this to convert from the standard form to the general form. This requires calculating 2h, 2k, h², k², and r², which often involves multiplying by 3-digit numbers. General Form Coefficients D = -2h, E = -2k, F = h² + k² - r² These formulas define the direct relationship between the center (h, k) and radius (r) from the standard form and the coefficients D, E, and F in the general form. Calculating F is where precise multiplication and addition of large numbers are crucial.

4 more steps in this tutorial

Sign up free to access the complete tutorial with worked examples and practice.

Sign Up Free to Continue

Sample Practice Questions

Challenging
The general form of a circle's equation is x² + y² - 270x - 320y + F = 0. If the circle passes through the origin (0,0), what is the value of r², the square of the radius?
A.0
B.43825
C.21525
D.87650
Challenging
Two circles are defined by C1: (x - 120)² + (y - 50)² = 30² and C2: (x - 120)² + (y - 50)² = 130². When both are converted to general form, what is the positive difference between their F coefficients (F_C2 - F_C1)?
A.16000
B.16900
C.900
D.100
Challenging
A circle has a general form x² + y² - 210x - 220y + 33125 = 0. If the radius of this circle is doubled, what will the new F coefficient be?
A.26250
B.3125
C.-16875
D.13125

Want to practice and check your answers?

Sign up to access all questions with instant feedback, explanations, and progress tracking.

Start Practicing Free

More from Circles in the coordinate plane

Ready to find your learning gaps?

Take a free diagnostic test and get a personalized learning plan in minutes.