7/24/2019 F_Finding Solutions in an Interval for a Trigonometric Equation With a Squared

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Kwadwo Amankwa - 02/29/2016 2:25:24 AM PSTPreCalculus / Amankwa, Kwadwo (Amankwa)

Finding solutions in an interval for a trigonometric equation with a squaredfunction: Problem type 2

Find all solutions of the equation in the interval .

Write your answer in radiansin terms of .

If there is more than one solution, separate them with commas.

We can factor the left-hand side of the equation.

The productof the factors and is .

So if the equation has a solution, at least one of the factors must be .

or

Cosine has the value at .

It neverhas the value .

The answer is .

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0, 2

=+cos2x +4cosx 3 0

=+cosx 1 +cosx 3 0

+cosx 1 +cosx 3 0

0

+cosx 1 = 0 +cosx 3 = 0

cosx = 1 cosx = 3

1

3

=x