GrAssign Solving Trig Eq using Desmos

(G) GrAssign - Solving Trig Equation using Desmos

~ Review the above lesson's process.

~ You are given 3 trig equations to solve.

~ Solve each equation using the previous lesson's algebraic methods (Ex 1 to Ex 3).

~ Record your work on the provided document: (Right --->.

~ You can use Notability to record your work on the above doc.

~ After you solve the equation, determine the angle's measure.

~ You will graph both the equation and its solution.

Look over the previous section's examples.

~ The points of intersection will be the solution(s) to the equation,

which should match your algebraic work.

~ Because the domain is [0, 2π], Desmos settings (image below) will be used for all equations.

10.4A_GrAssign_V2.pdf

Note: For the square root symbol, type the following: sqrt

(a square root symbol should appear, type the radicand)

For the symbol π, type the word pi. (Desmos will change it to π)

Set up Desmos grid, x-axis and y-axis as noted at left.

Assignment

Using the above example, complete the problems below.

Note: Answers should be within the given domain.

1. 2 cos2 x - cos x - 3 = 0 [0, 2π] Factor first

2. 4 sin2 x - 1 = 0 [0, 2π] Again, sin2x (+/-)

3. sin2 x - sin x = 0 [0, 2π] Factor first

Instructions

1. On the answer sheet, algebraically solve for x.

2. Determine the exact solutions - record as radians, no decimals.

(This must be completed before you use Desmos)

3. Using Desmos, graph the two expressions. (Reread the two notes in the above example.)

If there are two equations, both must be included in Desmos, which might result in 4 equations that need to be graphed.

4. Record the graphical solutions as a Desmos point, then click on the label box to make sure these solutions are visible.

i.e. x = (pi/3, 1/2) [see the above image]

5. Write a statement comparing your algebraic solution to the graph's points of intersection. Are your solutions correct?

If not, explain why not.

6. Take a screenshot of your equations, points, and the graph. (Include your name).

[See the graph image in the above example.]

7. After doing the 3 equations, explain what you learned using this method of finding solutions.

8. Using your TI grapher, graph problem #3 to determine if using a grapher would also help you find a trig equation's solution(s).

Briefly describe the results and your thoughts.

9. Save each problem as follows:

1_TrigEqDes_LastName

2_TrigEqDes_LastName

3_TrigEqDes_LastName

10. Upload to Google Classroom

11. Point value: 30 pts

Include the following at the top of your first page.

"I pledge my honor, I will not violate Nazareth's Honor Code during this assignment."

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