5. [tex] \cos (3x) = -1 [/tex]

Part I: Using an appropriate inverse trigonometric expression, write an equation that defines the value of [tex] 3x [/tex]. (2 points)



Answer :

To determine the value of [tex]\(3x\)[/tex] using an appropriate inverse trigonometric expression, we start with the given equation:

[tex]\[ \cos(3x) = -1 \][/tex]

We need to find the angle for which the cosine is [tex]\(-1\)[/tex]. In the unit circle, the angle where the cosine equals [tex]\(-1\)[/tex] is [tex]\( \pi \)[/tex] (180 degrees), plus any multiple of [tex]\(2\pi\)[/tex] (360 degrees), since cosine is periodic with a period of [tex]\(2\pi\)[/tex].

Therefore, the general solution for [tex]\(3x\)[/tex] can be written as:

[tex]\[ 3x = \pi + 2n\pi \][/tex]

where [tex]\(n\)[/tex] is any integer. This equation defines the set of all angles [tex]\(3x\)[/tex] that satisfy the original equation.