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Pearson Algebra 2 Common Core, 2011

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Pearson Algebra 2 Common Core, 2011 View details

2. Solving Trigonometric Equations Using Inverses

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Exercise 27 Page 916

Start by using the Zero Product Property. Then, draw the unit circle on the coordinate plane.

$\frac{π}{2}$ radians, $π$ radians, $\frac{3 π}{2}$ radians

Practice makes perfect

To solve the given equation, we will first use the Zero Product Property to solve for $cos θ .$ Then we will use the unit circle to find the exact values of $θ$ that satisfy the equation.

Solving the Equation for $cos θ$

Let's start by using the Zero Product Property to solve the equation for

cos θ .

(cos θ) (cos θ + 1) = 0

Use the Zero Product Property

cos θ = 0 cos θ + 1 = 0 (I) (II)

$(II):$ $LHS - 1 = RHS - 1$

cos θ = 0 cos θ = - 1

Finding the Exact Values of $θ$

We obtained two values for

cos θ .

The cosine of an angle in standard position is the

x -

coordinate of the point of intersection

P

of its terminal side and the unit circle.

Subchapter links

Lesson Check p.915

Practice and Problem-Solving Exercises p.916-918

Standardized Test Prep p.918

Mixed Review p.918