Respuesta :

Answer:

x=13.38

Step-by-step explanation:

Hi there!

We are given triangle ABC, with m<A=45°, CA=13, and BA=x

We want to find the value of x

First, let's find out which side is the adjacent, opposite, and hypotenuse

Using <A as the reference angle:

BC is the opposite

CA is the adjacent

BA is the hypotenuse

Recall the 3 most common trigonometric functions:

Sine is [tex]\frac{opposite}{hypotenuse}[/tex]

Cosine is [tex]\frac{adjacent}{hypotenuse}[/tex]

Tangent is [tex]\frac{opposite}{adjacent}[/tex]

Since we know the values of both the adjacent and the hypotenuse, let's use the cosine of <A

In reference to <A, the ratio will be:

cos(<A)=[tex]\frac{CA}{BA}[/tex]

Substituting all known values gives:

cos(45)=[tex]\frac{13}{x}[/tex]

Now multiply both sides by x

cos(45)x=13

Divide both sides by cos(45)

x=[tex]\frac{13}{cos(45)}[/tex]

Now plug [tex]\frac{13}{cos(45)}[/tex] into your calculator. Make sure that the calculator is in degree mode

x≈13.38

Hope this helps!