Digital SAT Math - Desmos Lesson #1 Solve any Equation!

Tutorllini Test Prep
11 Nov 202205:54

TLDRIn this tutorial, Tutorlini Test Prep demonstrates how to use Desmos for solving equations on the digital SAT Math section. The instructor explains that by graphing the left and right sides of an equation, one can find their intersection points to solve for 'x'. The video walks through several examples, showing how to use Desmos' features like zooming and graphing to identify solutions. The instructor also advises bringing a mouse for test day for easier navigation. The video concludes by highlighting Desmos' utility for solving complex equations without guesswork.

Takeaways

  • 📐 Use Desmos to solve equations for the digital SAT Math section by graphing 'y =' the left and right sides of the equation.
  • 🖱 It's recommended to bring a mouse for test day to make it easier to interact with Desmos.
  • 🔍 Use the scroll wheel to zoom in and out to find the points of intersection on the graph.
  • ✏ Focus on the X values at the points of intersection, as these are the solutions to the equation.
  • 📝 For multiple-choice questions, only the positive solution is typically required.
  • 🔢 Convert decimal solutions to fractions if necessary, using Desmos' fraction button.
  • 📉 When the graphs are hard to see, zoom out to locate the intersection points.
  • 🔄 Practice using Desmos by pausing the video and attempting to solve the equations yourself.
  • 🎯 Desmos can be used to solve any equation, even those without multiple-choice answers, reducing the need for guesswork.
  • 👚‍🏫 The tutor offers services for all sections of the SAT and math subjects from 7th grade to AP/early college level.

Q & A

  • What is the main topic of the video?

    -The main topic of the video is how to use Desmos for solving equations on the digital SAT Math.

  • What is the first step in solving an equation using Desmos according to the video?

    -The first step is to graph 'y equals the left-hand side of the equation' and 'y equals the right-hand side of the equation' on Desmos.

  • Why is it recommended to bring a mouse on the test day when using Desmos?

    -It is recommended to bring a mouse because it's easier to click, drag, and move around, and the scroll wheel can be used to zoom in and out to find points of intersection.

  • What does the tutor demonstrate as the first problem in the video?

    -The tutor demonstrates solving the equation '55/x + 6 = x' as the first problem.

  • What are the x-values of the intersection points for the first problem?

    -The x-values of the intersection points for the first problem are -11 and 5.

  • How does the tutor handle the second problem where the graphs are not immediately visible?

    -The tutor zooms out using the scroll wheel to make the graphs visible and then identifies the points of intersection.

  • What is the equation for the second problem demonstrated in the video?

    -The equation for the second problem is 'y = -4x^2 - 7x' and 'y = -36'.

  • What are the x-values of the intersection points for the second problem?

    -The x-values of the intersection points for the second problem are -4 and 2.25.

  • How does the tutor solve the absolute value equation in the third problem?

    -The tutor solves the absolute value equation by using the absolute value button in the function menu or by holding shift and pressing the key above enter.

  • What is the equation for the third problem demonstrated in the video?

    -The equation for the third problem is 'y = |4 - x| + 3' and 'y = 25'.

  • What are the x-values of the intersection points for the third problem?

    -The x-values of the intersection points for the third problem are -1 and 9.

  • What is the final advice given by the tutor regarding solving equations on the SAT using Desmos?

    -The final advice is that Desmos can be used to solve any equation on the test, eliminating the need for guess and check, especially for free response questions without multiple-choice answers.

Outlines

00:00

📚 Introduction to Desmos for SAT Math

The video begins with a tutorial on using Desmos for solving equations on the digital SAT Math test. The presenter explains that Desmos can be used to solve any equation by graphing the left and right sides of the equation and finding their intersection points. The first example involves solving the equation 55/X + 6 = X, where the intersections are found at X values of -11 and 5. The presenter emphasizes the importance of using a mouse for ease of navigation and zooming in Desmos. The video encourages viewers to practice using Desmos by pausing and attempting to solve the equations themselves.

05:04

🔍 Advanced Desmos Techniques for SAT Math

In the second paragraph, the presenter demonstrates how to use Desmos for more complex equations, such as negative 4x squared minus seven X equals negative 36. The video shows how to zoom out to find intersection points that are not immediately visible and how to label these points for clarity. The presenter also shows how to convert decimal answers into fractions using Desmos' features. The solutions for this equation are X values of -4 and 2.25, with the latter being converted into the fraction 9/4. The video concludes with another example involving absolute value equations, where the solutions are X values of -1 and 9, and the positive solution of 9 is selected as the final answer. The presenter highlights the usefulness of Desmos for solving any equation on the SAT, including free-response questions, thus eliminating the need for guesswork.

Mindmap

Keywords

💡Desmos

Desmos is an online graphing calculator that allows users to plot mathematical functions and equations. In the context of the video, Desmos is used as a tool to solve equations for the digital SAT Math section. The tutor demonstrates how to graph both sides of an equation to find their intersection points, which represent the solutions to the equation.

💡Digital SAT Math

The digital SAT Math refers to the section of the SAT (Scholastic Assessment Test) that is administered in a digital format. The video is specifically focused on how to use Desmos to solve math problems within this digital environment. It highlights the advantages of using Desmos over traditional methods, such as the ability to graph and find solutions more visually.

💡Graphing

Graphing is the process of plotting data points on a graph to visualize the relationship between variables. In the video, graphing is used to solve equations by plotting the left and right sides of an equation on the same graph to find their intersection points, which are the solutions to the equations.

💡Intersection Points

Intersection points are the points where two or more graphs meet. In the context of the video, finding the intersection points of the left and right sides of an equation is crucial for solving the equation. The tutor demonstrates how to use Desmos to identify these points and extract the x-values as the solutions.

💡Mouse

A mouse is a pointing device used with computers to control a cursor on the screen. The video suggests bringing a mouse to the test day for the digital SAT Math because it facilitates easier navigation and manipulation within Desmos, such as clicking, dragging, and zooming in and out to find intersection points.

💡Zoom In/Out

Zooming in and out refers to the action of adjusting the magnification level of a display to make objects appear closer or farther away. In the video, the tutor uses the scroll wheel to zoom in and out on the Desmos graph to better locate and identify the intersection points of the plotted equations.

💡Scroll Wheel

The scroll wheel is a feature on many computer mice that allows for vertical scrolling by rolling the wheel. In the video, the tutor uses the scroll wheel to zoom in and out on the Desmos graph, which is essential for finding the intersection points of the equations when they are not immediately visible.

💡Positive Solution

A positive solution refers to a solution that is greater than zero. In the context of the video, when solving equations, the tutor is often asked to provide the positive solution, which is one of the x-values that is greater than zero. This is relevant in multiple-choice questions where only one answer is correct.

💡Absolute Value

Absolute value is a mathematical concept that represents the distance of a number from zero on the number line, regardless of direction. In the video, the tutor demonstrates how to graph an equation involving absolute values by using the absolute value function in Desmos, which is represented by vertical lines on either side of the equation.

💡Free Response

Free response refers to a type of question on the SAT where students are required to provide a written or calculated answer without multiple-choice options. The video emphasizes that Desmos can be used to solve free response questions in the digital SAT Math section, eliminating the need for guesswork.

Highlights

Introduction to using Desmos for solving equations on the digital SAT Math.

Desmos can solve any equation by graphing the left and right sides.

Example problem: Solve 55/X + 6 = X using Desmos.

Graphing y = 55/X + 6 and y = X to find intersection points.

Using a mouse can improve ease of use on test day.

Zooming in and out helps identify points of intersection.

Solution to the example problem: x = -11 and x = 5.

Focus on the X values for the solution.

Positive solution for the example is x = 5.

Encouragement to practice using Desmos for more problems.

Next example: Solve -4x^2 - 7x = -36 using Desmos.

Adjusting graph view to find intersection points.

Solution: x = -4 and x = 9/4, with the positive solution being 9/4.

Demonstration of converting a decimal to a fraction in Desmos.

Last example: Solve |4 - x| + 3 = 25 using Desmos.

Using the absolute value function in Desmos.

Solution: x = -1 and x = 9, with the positive solution being 9.

Desmos helps solve equations without guessing and checking.

Desmos can solve any equation on the test, even free response ones.

Information about the tutor's services and website provided.

Conclusion and call to action for likes and subscriptions.