Question

Based on the image below, if you know that , find the following:

a) sin A
b) cos A
c) tan A
d) tan B

Answer 1

A. Sine A = 4/5

B. Cos A = 3/5

C. Tan A = 4/3

D. Tan B = 3/4

Explanation:

We'll begin by calculating the value of b in the attached photo.

This can be obtained as follow:

Cos B = 4/5

Cos B = Adjacent /Hypothenus

Adjacent = 4

Hypothenus = 5

Using pythagoras theory, the value of b can be obtained as follow:

b² = 5² – 4²

b² = 25 – 16

b² = 9

Take the square root of both side.

b = √9

b = 3

A. Determination of Sine A

Sine A =?

Opposite = 4

Hypothenus = 5

Sine A = Opposite /Hypothenus

Sine A = 4/5

B. Determination of Cos A

Cos A =?

Adjacent = 3

Hypothenus = 5

Cos A = Adjacent /Hypothenus

Cos A = 3/5

C. Determination of Tan A.

Tan A =?

Opposite = 4

Adjacent = 3

Tan A = Opposite /Adjacent

Tan A = 4/3

D. Determination of Tan B

Tan B =?

Opposite = 3

Adjacent = 4

Tan B = Opposite /Adjacent

Tan B = 3/4