I dont understand this

Question

asked Jul 2, 2020 227k views

1 Answer

Pomber · Answer 1 · 2020-07-07T01:04:14+0000

Answer: First option.

Explanation:

You need to remember the following Trigonometric Identity:

$cos\alpha =(adjacent)/(hypotenuse)$

In this case, you can identify in the figure that:

$\alpha =35\°\\adjacent=9\\hypotenuse=x$

Then you must substitute these values into
$cos\alpha =(adjacent)/(hypotenuse)$ :

$cos(35\°) =(9)/(x)$

Finally, you need to solve for "x" in order to find its value. This is:

$(x)(cos(35\°))=9\\\\x=(9)/(cos(35\°))\\\\x=10.98$

Rounding the result to the nearest tenth, you get:

$x\approx11$