Question

Determine whether each expression can be used to find the length of side AB. Match Yes or No for each

Answer 1

Answer:

$(a)\ AB = \frac{7}{\sin (B)}$  $\to Yes$

$(b)\ AB = \frac{24}{\cos (B)}$ $\to Yes$

$(c)\ AB = \frac{24}{\cos (A)}$ $\to No$

$(d)\ AB = \frac{7}{\cos (A)}$  $\to Yes$

Step-by-step explanation:

Given

$BC =24$

$AC = 7$

Required

Select Yes or No for the given options

$(a)\ AB = \frac{7}{\sin (B)}$  $\to Yes$

Considering the sine of angle B, we have:

$\sin(B) = \frac{Opposite}{Hypotenuse}$

$\sin(B) = \frac{7}{AB}$

Make AB, the subject

$AB = \frac{7}{\sin(B)}$

$(b)\ AB = \frac{24}{\cos (B)}$ $\to Yes$

Considering the cosine of angle B, we have:

$\cos(B) = \frac{Adjacent}{Hypotenuse}$

$\cos(B) = \frac{24}{AB}$

Make AB the subject

$AB = \frac{24}{\cos(B)}$

$(c)\ AB = \frac{24}{\cos (A)}$ $\to No$

Considering the cosine of angle B, we have:

$\cos(A) = \frac{Adjacent}{Hypotenuse}$

$\cos(A) = \frac{7}{AB}$

Make AB the subject

$AB = \frac{7}{\cos(A)}$

$(d)\ AB = \frac{7}{\cos (A)}$  $\to Yes$

This has been shown in (c) above