(b) Solve [tex]3 - 2 \sin x = \frac{13}{4}[/tex] for [tex]0^{\circ} \leq x \leq 360^{\circ}[/tex].

[tex]x = [/tex] or [tex]x = [/tex]



Answer :

To solve the equation [tex]\(3 - 2 \sin x = \frac{13}{4}\)[/tex] for [tex]\(0^\circ \leq x \leq 360^\circ\)[/tex], follow these steps:

1. Isolate the trigonometric function.

Start by isolating [tex]\(\sin x\)[/tex]:
[tex]\[ 3 - 2 \sin x = \frac{13}{4} \][/tex]
Subtract 3 from both sides:
[tex]\[ -2 \sin x = \frac{13}{4} - 3 \][/tex]
Simplify the right-hand side:
[tex]\[ -2 \sin x = \frac{13}{4} - \frac{12}{4} = \frac{1}{4} \][/tex]

2. Solve for [tex]\(\sin x\)[/tex].

Divide both sides by -2:
[tex]\[ \sin x = -\frac{1}{8} \][/tex]

3. Determine the general solutions.

The solution to [tex]\(\sin x = -\frac{1}{8}\)[/tex] in the interval [tex]\(0^\circ \leq x \leq 360^\circ\)[/tex] involves finding the reference angle and considering the quadrants where the sine function is negative (i.e., the third and fourth quadrants).

Compute the reference angle:
[tex]\[ \theta = \arcsin\left(\frac{1}{8}\right) \][/tex]
Approximate using a calculator:
[tex]\[ \theta \approx 7.18^\circ \][/tex]

4. Find the specific solutions in the required interval.

Since sine is negative in the third and fourth quadrants, the angles will be:
[tex]\[ x = 180^\circ + \theta \quad \text{(Third quadrant)} \][/tex]
[tex]\[ x = 360^\circ - \theta \quad \text{(Fourth quadrant)} \][/tex]

Substitute [tex]\(\theta \approx 7.18^\circ\)[/tex]:
[tex]\[ x \approx 180^\circ + 7.18^\circ = 187.18^\circ \][/tex]
[tex]\[ x \approx 360^\circ - 7.18^\circ = 352.82^\circ \][/tex]

5. Write the final solutions.

Therefore, the solutions in the interval [tex]\(0^\circ \leq x \leq 360^\circ\)[/tex] are:
[tex]\[ x \approx 187.18^\circ \quad \text{and} \quad x \approx 352.82^\circ \][/tex]

So, the final solutions for [tex]\( x \)[/tex] are:
[tex]\[ x \approx 187.18^\circ \quad \text{or} \quad 352.82^\circ \][/tex]