Question

Fill in the blank. If necessary, use the slash mark ( / ) for a fraction bar.
If sin theta = 3/5, then cose theta = ?

Answer 1

Answer:

cos Ф = adj / hyp could be either 4/5 or -4/5.

Step-by-step explanation:

If sin Ф = 3/5, then we can assume that the opposite side is 3 and the hypotenuse is 5.  Using the Pythagorean Theorem, we find that the adjacent side is 4:  

√(5² - 3²) = √16 = ±4.

cos Ф = adj / hyp could be either 4/5 or -4/5.

Answer 2

Answer:

$\frac{4}{5}$

Step-by-step explanation:

Given,

$sin \theta = \frac{3}{5}$

$\because sin \theta =\frac{\text{Opposite side of }\theta}{\text{Hypotenuse }}$

By comparing,

Opposite side of $\theta$ = 3

Hypotenuse = 5,

By pythagoras theorem,

Adjacent side of $\theta$ = $\sqrt{5^2 - 3^2}=\sqrt{25-9}=\sqrt{16}=4$

Now,

$cos \theta =\frac{\text{Adjacent side of }\theta}{\text{Hypotenuse }}$

$\implies cos \theta=\frac{4}{5}$