the graph of y = cos x and the line y = (-1)/2 over the interval [0,2 pi]. Where do the two graphs intersect? Give exact answers in radians,
+26387 the graph of y = cos x and the line y = (-1)/2 over the interval [0,2 pi]. Where do the two graphs intersect? Give exact answers in radians,
$$\small{\text{$
\begin{array}{rcll}
\cos{(x)} &=& -\frac12 \\\\
\cos{(x)} &=& -\frac12 & \qquad | \qquad \pm\arccos{} \\\\
x_{1,2} &=& \pm \arccos{(-\frac12 )}\\\\
x_{1,2} &=& \pm 120 \ensurement{^{\circ}} \\\\
x_{1} &=& 120 \ensurement{^{\circ}} \\\\
x_1 &=& \frac{2}{3}\cdot \pi \\\\\\
x_2 &=& -120\ensurement{^{\circ}} + 360 \ensurement{^{\circ}} \\\\
x_2 &=& 240 \ensurement{^{\circ}} \\\\
x_2 &=& \frac{4}{3}\cdot \pi
\end{array}
$}}$$
+26387 the graph of y = cos x and the line y = (-1)/2 over the interval [0,2 pi]. Where do the two graphs intersect? Give exact answers in radians,
$$\small{\text{$
\begin{array}{rcll}
\cos{(x)} &=& -\frac12 \\\\
\cos{(x)} &=& -\frac12 & \qquad | \qquad \pm\arccos{} \\\\
x_{1,2} &=& \pm \arccos{(-\frac12 )}\\\\
x_{1,2} &=& \pm 120 \ensurement{^{\circ}} \\\\
x_{1} &=& 120 \ensurement{^{\circ}} \\\\
x_1 &=& \frac{2}{3}\cdot \pi \\\\\\
x_2 &=& -120\ensurement{^{\circ}} + 360 \ensurement{^{\circ}} \\\\
x_2 &=& 240 \ensurement{^{\circ}} \\\\
x_2 &=& \frac{4}{3}\cdot \pi
\end{array}
$}}$$
