Question

the equation $cos^{-1}left(\frac{3.4}{10}
ight)=x$ can be used to determine the measure of angle bac.
what is the degree measure of angle bac? round to the nearest whole degree.
$\bigcirc$ $19^circ$
$\bigcirc$ $20^circ$
$\bigcirc$ $70^circ$
$\bigcirc$ $71^circ$

Explanation:

Step1: Simplify the fraction

$\frac{3.4}{10}=0.34$

Step2: Calculate inverse cosine

$x = \cos^{-1}(0.34)$

Step3: Round to whole degree

Use a calculator to find $\cos^{-1}(0.34) \approx 70.12^\circ$, which rounds to $70^\circ$.

Answer:

70°