135k views
3 votes
Please help me! thanks

Please help me! thanks-example-1

2 Answers

2 votes

Answer:

x = 5.41

Explanation:

To find the measure of side x, we can use the cosine trigonometric ratio:


\boxed{\begin{array}{l}\underline{\textsf{Cosine trigonometric ratio}}\\\\\sf \cos(\theta)=(A)/(H)\\\\\textsf{where:}\\\phantom{ww}\bullet\;\textsf{$\theta$ is the angle.}\\\phantom{ww}\bullet\;\textsf{$A$ is the side adjacent the angle.}\\\phantom{ww}\bullet\;\textsf{$H$ is the hypotenuse (the side opposite the right angle).}\end{array}}

In this case:

  • θ = 78°
  • A = x
  • H = 26

Substitute the values into the cosine ratio:


\cos (78^(\circ))=(x)/(26)

Multiply both sides of the equation by 26 to isolate x:


x=26\cos (78^(\circ))

Evaluate using a calculator:


x=5.40570396...

Finally, round to the nearest hundreth:


\Large\boxed{\boxed{x = 5.41}}

User Zborovskaya
by
8.1k points
2 votes

The value of x is 5.41.

To find the measure of X in the given scenario, where X is the length of a side in a right-angled triangle and the angle opposite to it is
\( 26^\circ \), the cosine function is utilized.

The cosine of an angle in a right-angled triangle is defined as the ratio of the adjacent side to the hypotenuse. In this case, the adjacent side is x and the hypotenuse is
\( 78^\circ \). The cosine of an angle
\( \theta \)is given by the formula:


\[ \cos(\theta) = \frac{\text{Adjacent}}{\text{Hypotenuse}} \]

For this problem:


\[ \cos(26^\circ) = (x)/(78^\circ) \]

To solve for x, rearrange the equation:


\[ x = 78^\circ \cdot \cos(26^\circ) \]

Using a calculator, evaluate
\( \cos(26^\circ) \), and then multiply it by
\( 78^\circ \)to find x. Rounding to the nearest hundredth, the answer is approximately x = 5.41 .

User Juanillo
by
8.7k points