Answer:
Person will be 24 metres above the ground after 1.50 minutes
Step-by-step explanation:
Given:
[tex]h(t)=18.8-16.7\cos \left ( \frac{2\pi t}{5} \right )[/tex]
To find:
time when the person be 24 meters above the ground
Solution:
Put [tex]h(t)=24[/tex]
[tex]h(t)=18.8-16.7\cos \left ( \frac{2\pi t}{5} \right )\\24=18.8-16.7\cos \left ( \frac{2\pi t}{5} \right )\\16.7\cos \left ( \frac{2\pi t}{5} \right )=18.8-24\\16.7\cos \left ( \frac{2\pi t}{5} \right )=-5.2\\\cos \left ( \frac{2\pi t}{5} \right )=\frac{-5.2}{16.7}\\\cos \left ( \frac{2\pi t}{5} \right )=-0.3114\\\frac{2\pi t}{5}=1.887\\\frac{2}{5}\times \frac{22}{7}t=1.887\\t=1.887\times \frac{5}{2}\times \frac{7}{22}\\=1.501\\\approx 1.50 \,\,minute[/tex]
So, the person will be 24 metres above the ground after 1.50 minutes