<h2>
Question:</h2>
Find the values of the sine, cosine, and tangent for ∠A
a. sin A =
, cos A =
, tan A = ![\frac{2 }{3}](https://tex.z-dn.net/?f=%5Cfrac%7B2%20%7D%7B3%7D)
b. sin A =
, cos A =
, tan A = ![\frac{3}{2}](https://tex.z-dn.net/?f=%5Cfrac%7B3%7D%7B2%7D)
c. sin A =
, cos A =
, tan A = ![\frac{3}{2}](https://tex.z-dn.net/?f=%5Cfrac%7B3%7D%7B2%7D)
d. sin A =
, cos A =
, tan A = ![\frac{2 }{3}](https://tex.z-dn.net/?f=%5Cfrac%7B2%20%7D%7B3%7D)
<h2>
Answer:</h2>
d. sin A =
, cos A =
, tan A = ![\frac{2 }{3}](https://tex.z-dn.net/?f=%5Cfrac%7B2%20%7D%7B3%7D)
<h2>
Step-by-step explanation:</h2>
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;
<em>i. First calculate the value of the missing side AB.</em>
<em>Using Pythagoras' theorem;</em>
⇒ (AB)² = (AC)² + (BC)²
<em>Substitute the values of AC and BC</em>
⇒ (AB)² = (36)² + (24)²
<em>Solve for AB</em>
⇒ (AB)² = 1296 + 576
⇒ (AB)² = 1872
⇒ AB = ![\sqrt{1872}](https://tex.z-dn.net/?f=%5Csqrt%7B1872%7D)
⇒ AB =
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
ft (43.27ft).
<em>ii. Calculate the sine of ∠A (i.e sin A)</em>
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 =
-------------(i)
<em>In this case,</em>
Ф = A
opposite = 24ft (This is the opposite side to angle A)
hypotenuse =
ft (This is the longest side of the triangle)
<em>Substitute these values into equation (i) as follows;</em>
sin A = ![\frac{24}{12\sqrt{13} }](https://tex.z-dn.net/?f=%5Cfrac%7B24%7D%7B12%5Csqrt%7B13%7D%20%7D)
sin A = ![\frac{2}{\sqrt{13}}](https://tex.z-dn.net/?f=%5Cfrac%7B2%7D%7B%5Csqrt%7B13%7D%7D)
<em>Rationalize the result by multiplying both the numerator and denominator by </em>
<em />
sin A =
sin A = ![\frac{2\sqrt{13} }{13}](https://tex.z-dn.net/?f=%5Cfrac%7B2%5Csqrt%7B13%7D%20%7D%7B13%7D)
<em>iii. Calculate the cosine of ∠A (i.e cos A)</em>
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 =
-------------(ii)
<em>In this case,</em>
Ф = A
adjacent = 36ft (This is the adjecent side to angle A)
hypotenuse =
ft (This is the longest side of the triangle)
<em>Substitute these values into equation (ii) as follows;</em>
cos A = ![\frac{36}{12\sqrt{13} }](https://tex.z-dn.net/?f=%5Cfrac%7B36%7D%7B12%5Csqrt%7B13%7D%20%7D)
cos A = ![\frac{3}{\sqrt{13}}](https://tex.z-dn.net/?f=%5Cfrac%7B3%7D%7B%5Csqrt%7B13%7D%7D)
<em>Rationalize the result by multiplying both the numerator and denominator by </em>
<em />
cos A =
cos A = ![\frac{3\sqrt{13} }{13}](https://tex.z-dn.net/?f=%5Cfrac%7B3%5Csqrt%7B13%7D%20%7D%7B13%7D)
<em>iii. Calculate the tangent of ∠A (i.e tan A)</em>
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 =
-------------(iii)
<em>In this case,</em>
Ф = A
opposite = 24 ft (This is the opposite side to angle A)
adjacent = 36 ft (This is the adjacent side to angle A)
<em>Substitute these values into equation (iii) as follows;</em>
tan A = ![\frac{24}{36}](https://tex.z-dn.net/?f=%5Cfrac%7B24%7D%7B36%7D)
tan A = ![\frac{2}{3}](https://tex.z-dn.net/?f=%5Cfrac%7B2%7D%7B3%7D)