Welcome to this week's lesson on Solving Quadratic Equations using Square Roots. Below you will find a summary of the concepts covered in class, detailed examples from the notes, and the homework schedule for the week.
Key Concepts: The Square Root Property
When solving an equation where the variable is squared (like $x^2$) or part of a squared group (like $(x+3)^2$), we can use the Square Root Property. Here is the step-by-step process we practiced in class:
- Isolate the Squared Term: Get the $x^2$ or the parenthesis group by itself on one side of the equation.
- Take the Square Root: Take the square root of both sides to cancel out the square.
- Remember the Plus/Minus ($\\pm$): This is crucial! When you take the square root of a variable squared, the answer can be positive or negative.
- Simplify the Radical: Use factor trees to break down non-perfect squares (e.g., $\\sqrt{40}$ becomes $2\\sqrt{10}$).
Examples from Class Notes
Here are a few examples we worked through in the attached notes:
1. Simple Quadratic:
$$x^2 - 100 = 0$$ $$x^2 = 100$$ $$x = \\pm\\sqrt{100}$$ $$x = \\pm 10$$2. Simplifying Radicals:
$$x^2 - 40 = 0$$ $$x^2 = 40$$ $$x = \\pm\\sqrt{40}$$(Using a factor tree, we know $40 = 4 \\cdot 10$, and the square root of 4 is 2)
$$x = \\pm 2\\sqrt{10}$$3. Binomial Squared:
$$(x+5)^2 = 9$$ $$\\sqrt{(x+5)^2} = \\sqrt{9}$$ $$x + 5 = \\pm 3$$(This splits into two equations: $x+5=3$ and $x+5=-3$)
$$x = -2 \\text{ or } -8$$Homework Assignment
Please refer to the attached Worksheet: Solving Quadratic Equations: Square Root Law. The assignment is split over two days:
- Part 1: Problems #1-10
- Part 2: Problems #11-20
- Due Date: The full homework packet is due on Monday, April 21st.
Important Announcements
Due to my absence on Thursday afternoon and Friday, there will be no quiz on Monday. Instead, I will be grading 5 random questions from the homework assignment to count as a quiz grade. Please ensure all your work is shown clearly!
If you are struggling with these concepts, I highly recommend reviewing the relevant topics on Khan Academy or watching the supplementary videos posted below. If you do not completely understand the material, please come and ask for help!