Which of the following values of [tex]$x$[/tex] is a solution of the given equation?

[tex]\[ (6 \cos (x) - 5 \sin (x))^2 + 11 \sin^2(x) = 36 \][/tex]

A. [tex] x = \frac{\pi}{2} [/tex]
B. [tex] x = \pi [/tex]
C. [tex] x = \frac{3\pi}{2} [/tex]
D. [tex] x = 2\pi [/tex]



Answer :

To determine which values of [tex]\( x \)[/tex] are solutions to the given equation

[tex]\[ (6 \cos(x) - 5 \sin(x))^2 + 11 \sin^2(x) = 36, \][/tex]

we go through the following steps:

1. Express the given equation:
The equation we need to solve is:
[tex]\[ (6 \cos(x) - 5 \sin(x))^2 + 11 \sin^2(x) = 36. \][/tex]

2. Set up the equation:
Let's denote the left-hand side of the equation as:
[tex]\[ f(x) = (6 \cos(x) - 5 \sin(x))^2 + 11 \sin^2(x). \][/tex]

3. Possible values of [tex]\( x \)[/tex]:
Based on solving the equation, we find that the solutions for [tex]\( x \)[/tex] are:
[tex]\[ x = 0, \quad x = -\frac{\pi}{2}, \quad x = \frac{\pi}{2}. \][/tex]

These values of [tex]\( x \)[/tex] make the equation true when substituted back. Hence, the values of [tex]\( x \)[/tex] that are solutions to the given trigonometric equation are:

[tex]\[ x = 0, \quad x = -\frac{\pi}{2}, \quad x = \frac{\pi}{2}. \][/tex]

Thus, the correct options are:
[tex]\( x = 0, -\frac{\pi}{2}, \frac{\pi}{2} \)[/tex].