ShmoopTube
Where Monty Python meets your 10th grade teacher.
Search Thousands of Shmoop Videos
Square Roots Videos 13 videos
Number Sense: Drill Set 5, Problem 5. Between which two integers does the square root of 80 lie?
Number Sense: Drill Set 6, Problem 1. The root being squared must be between which two numbers?
Number Sense: Drill Set 6, Problem 2. The square root of 35 is between which of the following numbers?
ACT Math 4.2 Intermediate Algebra 433 Views
Share It!
Description:
ACT Math: Intermediate Algebra Drill 4, Problem 2. What is the root of this equation?
- Intermediate Algebra / Roots of polynomials
- Intermediate Algebra / Quadratic equations (Quadratic Formula)
- Product Type / ACT Math
- Foreign Language / Arabic Subtitled
- Foreign Language / Korean Subtitled
- Foreign Language / Chinese Subtitled
- Foreign Language / Spanish Subtitled
- Intermediate Algebra / Quadratic formula
Transcript
- 00:02
And here is your shmoop de jour...
- 00:06
What is a root of this equation? y2 - y = 4
- 00:10
And here are the potential answers...
- 00:16
OK so what is this question asking?
- 00:18
Sneaky quadratic equation question. We need to pull the root numbers and plug them in
Full Transcript
- 00:25
and see what we get. Remember the quadratic equation? Our old buddy,
- 00:29
old pal? When an equation is in the form ax squared
- 00:33
plus bx plus c equals 0... ...the solution can be negative b plus or
- 00:39
minus radical, b-squared minus 4ac all over 2a.
- 00:45
That's the quadratic equation formula.
- 00:47
That's a mouthful. Let's change the equation to y squared minus y minus
- 00:57
4 equals 0... so it looks like ax squared plus bx plus c equals 0.
- 01:06
We can see that a is 1, b is negative 1, and c is negative 4.
- 01:11
When we start pluggin', we get that 1 plus or minus the square root of 1 minus 4 times
- 01:22
1 times negative 4 all over 2... ...gives us 1 plus or minus the square root
- 01:29
of 17 over 2. So now we have one solution, or root, of the equation.
- 01:34
Looks like D.
Related Videos
ACT Math: Intermediate Algebra: Drill 3, Problem 1. Find the fifth number in the series.
ACT Math: Coordinate Geometry Drill 1, Problem 1. Which inequality is expressed by the number line?
ACT Math: Plane Geometry Drill 3, Problem 1. What is the area of the trapezoid shape in the video?
We don't like knocking people down to size, but we do like simplifying radicals. Join us?
If fleeing criminals always fled the scene of the crime at perfect right angles, it would be much easier to determine their whereabouts. Fortunatel...