Questions: Use the trigonometric substitution to write the algebraic equation as a trigonometric equation of (theta), where (-pi / 2<theta<pi / 2).
(4=sqrt16-x^2, x=4 sin theta )
(4=sqrt16-(4 sin (theta))^2)
Find (sin theta) and (cos theta). (Enter your answers as a comma-separated list.)
(sin theta=)
(cos theta=)
Transcript text: Use the trigonometric substitution to write the algebraic equation as a trigonometric equation of $\theta$, where $-\pi / 2<\theta<\pi / 2$.
\[
\begin{array}{r}
4=\sqrt{16-x^{2}}, x=4 \sin \theta \\
4=\sqrt{16-(4 \sin (\theta))^{2}}
\end{array}
\]
Find $\sin \theta$ and $\cos \theta$. (Enter your answers as a comma-separated list.)
\[
\begin{array}{l}
\sin \theta=\square \\
\cos \theta=\square
\end{array}
\]
Solution
Solution Steps
To solve the given problem, we will use trigonometric substitution. The substitution given is \( x = 4 \sin \theta \). We will substitute this into the equation and simplify to find \(\sin \theta\). Then, using the Pythagorean identity, we will find \(\cos \theta\).
Step 1: Substitute and Simplify
We start with the equation given by the trigonometric substitution \( x = 4 \sin \theta \). Substituting this into the equation \( 4 = \sqrt{16 - x^2} \) gives us:
\[
4 = \sqrt{16 - (4 \sin \theta)^2}
\]
This simplifies to:
\[
4 = \sqrt{16 - 16 \sin^2 \theta}
\]
Step 2: Solve for \(\sin \theta\)
Squaring both sides of the equation results in:
\[
16 = 16 - 16 \sin^2 \theta
\]
Rearranging this gives:
\[
16 \sin^2 \theta = 0
\]
Thus, we find:
\[
\sin \theta = 0
\]
Step 3: Calculate \(\cos \theta\)
Using the Pythagorean identity \( \sin^2 \theta + \cos^2 \theta = 1 \), we can find \(\cos \theta\):
\[
\cos^2 \theta = 1 - \sin^2 \theta = 1 - 0^2 = 1
\]
Therefore, we have:
\[
\cos \theta = 1
\]
Final Answer
The values are:
\[
\sin \theta = 0, \quad \cos \theta = 1
\]
Thus, the final answer is:
\[
\boxed{0, 1}
\]