Question

Find sect 。A)B)op回?2121

Answer 1

We will operate as follows:

$x=\frac{\sqrt[]{21}}{5}$$y=\frac{2}{5}$

Then:

$r^2=(\frac{\sqrt[]{21}}{5})^2+(\frac{2}{5})^2\Rightarrow r=1$

Then we calculate cosine in order to determine the secant:

$\cos (\theta)=\frac{x}{r}\Rightarrow\cos (\theta)=\frac{\frac{\sqrt[]{21}}{5}}{1}\Rightarrow\cos (\theta)=\frac{\sqrt[]{21}}{5}$

Now, the secant:

$\sec (\theta)=\frac{1}{\cos(\theta)}\Rightarrow\sec (\theta)=\frac{1}{\frac{\sqrt[]{21}}{5}}$$\Rightarrow\sec (\theta)=\frac{5}{\sqrt[]{21}}=\frac{5\sqrt[]{21}}{21}$

So, the soluton would be option B.