8.3 Trig Equations - Mrs. Johnston · 2018. 4. 27. · Solve Trig Equations by substitution. Solve...
Transcript of 8.3 Trig Equations - Mrs. Johnston · 2018. 4. 27. · Solve Trig Equations by substitution. Solve...
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Solve Trigonometric Equations in basic form.
Solve Trig Equations by substitution.
Solve Trigonometric Equations by factoring.
4/27/2018Free template from
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Make sure you are in degree mode
◦ 1) identify the 2 quadrants where the answers fall
◦ 2) type the inverse function into your calculator and get an answer in degrees
◦ 3) use that answer to fill in your two triangles in the identified quadrants
◦ 4) convert both answers into radians
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Ex 2) Solve sin x = -0.75 Ex 3) tan x = 3
Ex 4) 8 cos x – 1 = 0
Ex 5) 3 cos x + 1 = 0
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Some equations are more complicated and require other strategies to solve.
If the equation contains an x with a coefficient, you will need to do substitution and replacement to get the correct answers
If there is a square in the equation, you will need to factor
1) Substitute u for the bx term
2) Solve for u, include all answers
3) Replace the u with bx
4) Solve for x by dividing all the pieces by b
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1) Substitute u for the trig expression
2) Factor the new u expression
3) Set each piece =0 and solve for u
4) Replace the u with the trig function
5) Solve the trig function
Remember each trig function may have multiple answers
Ex 9) 3 sin2 x – sin x – 2 = 0 Ex 10) 4 sin2 x + 5 sin x + 1 = 0