Mathematics Grade 11 15 min

Solve a quadratic equation using square roots

Solve a quadratic equation using square roots

What you'll learn

  • Identify at least 8 out of 10 common two-dimensional shapes (circle, square, triangle, rectangle, rhombus, pentagon, hexagon, octagon) when shown a picture of each.
  • Explain the difference between a square and a rectangle using the number of equal sides and angles, in their own words.
  • Draw and label a shape that has 3 sides and 3 angles (triangle).

Tutorial Preview

1

Introduction & Learning Objectives

Learning Objectives Identify quadratic equations that can be solved using the square root property. Isolate the squared term in a quadratic equation using inverse operations. Apply the square root property to find all possible solutions. Solve quadratic equations that result in two real solutions, including rational and irrational numbers. Solve quadratic equations that result in a single, repeated real solution. Solve quadratic equations that result in two complex solutions using the imaginary unit 'i'. How long would it take a dropped object to fall from the top of a 100-meter cliff? 🧗 The answer lies in a special type of quadratic equation you can solve in just a few steps! This tutorial focuses on the square root property, a powerful and direct method for sol...
2

Key Concepts & Vocabulary

TermDefinitionExample Quadratic EquationAn equation that can be written in the standard form ax² + bx + c = 0, where a, b, and c are constants and a ≠ 0.The equation 4x² - 9 = 0 is a quadratic equation where a=4, b=0, and c=-9. This type is ideal for solving with square roots. Square Root PropertyA principle stating that if a squared expression equals a constant, then the expression itself is equal to the positive and negative square root of that constant.If x² = 25, the Square Root Property tells us that x = ±√25, so x = 5 or x = -5. Isolating the Squared TermThe process of using inverse operations to get the part of the equation that is being squared (like x² or (x-2)²) by itself on one side of the equal sign.In 3(x-1)² - 12 = 0, you would add 12 and then divide by 3 to isolate (x-1)²,...
3

Core Formulas

The Square Root Property If X² = k, then X = \pm\sqrt{k} This is the fundamental rule for this method. After isolating the squared expression (X), you take the square root of the constant (k) on the other side. The '±' is critical as it accounts for both possible solutions. Square Root of a Negative Number For any positive real number k, \sqrt{-k} = i\sqrt{k} When the constant 'k' is negative, this rule allows you to express the solution using the imaginary unit 'i'. This is how you find complex solutions.

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
Solve for x in the equation 3(2x - 5)² - 12 = 0.
A.x = 7/2 and x = 3/2
B.x = 5/2 ± √2
C.x = 5 ± 2
D.x = 7/2
Challenging
Given the formula (x - h)² = k, where k ≥ 0, solve for x in terms of h and k.
A.x = h ± k
B.x = -h ± √k
C.x = h ± √k
D.x = ±√(k) - h
Challenging
Which of the following equations can be solved using the square root property after one algebraic step? Hint: Look for a perfect square trinomial.
A.x² + 8x + 10 = 0
B.x² - 10x + 25 = 49
C.2x² - 8x - 15 = 0
D.x² + 5x + 6 = 0

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 Quadratic functions

Mathematics for other grades

Frequently asked questions

What grade level is "Solve a quadratic equation using square roots"?

Solve a quadratic equation using square roots is a Grade 11 Mathematics lesson on ExcelOS.

What will I learn in Solve a quadratic equation using square roots?

You'll be able to: Identify at least 8 out of 10 common two-dimensional shapes (circle, square, triangle, rectangle, rhombus, pentagon, hexagon, octagon) when shown a picture of each; Explain the difference between a square and a rectangle using….

Is "Solve a quadratic equation using square roots" free to practice?

Yes. You can read the tutorial preview for free, and signing up for a free ExcelOS account unlocks the full tutorial and all practice questions with instant feedback.

How many practice questions are included with Solve a quadratic equation using square roots?

This lesson includes 25 practice questions across multiple difficulty levels, each with instant feedback and explanations.

Ready to find your learning gaps?

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