Question

Find the values of the sine, cosine, and tangent for ZA C A 36ft B 24ft

Answer 1

Question:

Find the values of the sine, cosine, and tangent for ∠A

a. sin A = $\frac{\sqrt{13} }{2}$,  cos A = $\frac{\sqrt{13} }{3}$,  tan A = $\frac{2 }{3}$

b. sin A = $3\frac{\sqrt{13} }{13}$,  cos A = $2\frac{\sqrt{13} }{13}$,  tan A = $\frac{3}{2}$

c. sin A = $\frac{\sqrt{13} }{3}$,  cos A = $\frac{\sqrt{13} }{2}$,  tan A = $\frac{3}{2}$

d. sin A = $2\frac{\sqrt{13} }{13}$,  cos A = $3\frac{\sqrt{13} }{13}$,  tan A = $\frac{2 }{3}$

Answer:

d. sin A = $2\frac{\sqrt{13} }{13}$,  cos A = $3\frac{\sqrt{13} }{13}$,  tan A = $\frac{2 }{3}$

Step-by-step explanation:

The triangle for the question has been attached to this response.

As shown in the triangle;

AC = 36ft

BC = 24ft

ACB = 90°

To calculate the values of the sine, cosine, and tangent of ∠A;

i. First calculate the value of the missing side AB.

Using Pythagoras' theorem;

⇒ (AB)² = (AC)² + (BC)²

Substitute the values of AC and BC

⇒ (AB)² = (36)² + (24)²

Solve for AB

⇒ (AB)² = 1296 + 576

⇒ (AB)² = 1872

⇒ AB = $\sqrt{1872}$

⇒ AB = $12\sqrt{13}$ ft

From the values of the sides, it can be noted that the side AB is the hypotenuse of the triangle since that is the longest side with a value of $12\sqrt{13}$ ft (43.27ft).

ii. Calculate the sine of ∠A (i.e sin A)

The sine of an angle (Ф) in a triangle is given by the ratio of the opposite side to that angle to the hypotenuse side of the triangle. i.e

sin Ф = $\frac{opposite}{hypotenuse}$             -------------(i)

In this case,

Ф = A

opposite = 24ft (This is the opposite side to angle A)

hypotenuse = $12\sqrt{13}$ ft (This is the longest side of the triangle)

Substitute these values into equation (i) as follows;

sin A = $\frac{24}{12\sqrt{13} }$

sin A = $\frac{2}{\sqrt{13}}$

Rationalize the result by multiplying both the numerator and denominator by $\sqrt{13}$

sin A = $\frac{2}{\sqrt{13}} * \frac{\sqrt{13} }{\sqrt{13} }$

sin A = $\frac{2\sqrt{13} }{13}$

iii. Calculate the cosine of ∠A (i.e cos A)

The cosine of an angle (Ф) in a triangle is given by the ratio of the adjacent side to that angle to the hypotenuse side of the triangle. i.e

cos Ф = $\frac{adjacent}{hypotenuse}$             -------------(ii)

In this case,

Ф = A

adjacent = 36ft (This is the adjecent side to angle A)

hypotenuse = $12\sqrt{13}$ ft (This is the longest side of the triangle)

Substitute these values into equation (ii) as follows;

cos A = $\frac{36}{12\sqrt{13} }$

cos A = $\frac{3}{\sqrt{13}}$

Rationalize the result by multiplying both the numerator and denominator by $\sqrt{13}$

cos A = $\frac{3}{\sqrt{13}} * \frac{\sqrt{13} }{\sqrt{13} }$

cos A = $\frac{3\sqrt{13} }{13}$

iii. Calculate the tangent of ∠A (i.e tan A)

The cosine of an angle (Ф) in a triangle is given by the ratio of the opposite side to that angle to the adjacent side of the triangle. i.e

tan Ф = $\frac{opposite}{adjacent}$             -------------(iii)

In this case,

Ф = A

opposite = 24 ft (This is the opposite side to angle A)

adjacent = 36 ft (This is the adjacent side to angle A)

Substitute these values into equation (iii) as follows;

tan A = $\frac{24}{36}$

tan A = $\frac{2}{3}$