All categories

3 years ago

In a triangle ABC, AB = 7, AC = 8, BC = 3, what is cos(A)?

1 answer:

6 0

Use the cosine rule.
c=AB=7
b=AC=8
a=BC=3
a^2=b^2+c^2-2bc(cos(A))
=>
cos(A)=(b^2+c^2-a^2)/(2bc)
=(7^2+8^2-3^2)/(2*7*8)
=13/14
=0.9286

You might be interested in

If the point A (6,9) is translated 4 units left, then find the new coordinates of the point A.

Alex_Xolod [135]

Answer:

(2, 9 )

Step-by-step explanation:

A translation of 4 units left is equivalent to subtracting 4 from the value of the x- coordinate, that is

(6, 9 ) → (6 - 4, 9 ) → (2, 9 )

6 0

3 years ago

F(x)=x^2. What is g(x)

Arisa [49]

Answer:

Step-by-step explanation:

7 0

2 years ago

The area of Mammoth Cave NationalPark in Kentucky is about fifty-two thousand, eight hundred thirty and nineteen hundredths acre

frutty [35]

Answer:it’s the first one

Step-by-step explanation:

4 0

2 years ago

<img src="https://tex.z-dn.net/?f=%28%20%5Cfrac%7B1%7D%7B2%7D%20%20%7Ba%7D%5E%7B2%7D%20%20%2B%20%20%20%5Cfrac%7B1%7D%7B2%7D%20ab

Zigmanuir [339]

Answer:

$\frac{1}{2}$ (a + 2b)(a - b)

Step-by-step explanation:

Assuming you require the expression to be factored

Given

$\frac{1}{2}$ a² + $\frac{1}{2}$ ab - b² ← factor out $\frac{1}{2}$ from each term

= $\frac{1}{2}$ (a² + ab - 2b²) ← factor the quadratic

Consider the factors of the coefficient of the b² term(- 2) which sum to give the coefficient of the ab- term (+ 1)

The factors are + 2 and - 1, since

2 × - 1 = - 2 and 2 - 1 = + 1, thus

a² + ab - 2b² = (a + 2b)(a - b) and

$\frac{1}{2}$ a² + $\frac{1}{2}$ ab - b² = $\frac{1}{2}$ (a + 2b)(a - b)

5 0

3 years ago

A line that crosses segment at right angles while dividing the segment in half is called

iren [92.7K]

The correct answer is:

A line that crosses segment at right angles while dividing the segment in half is called <u>a perpendicular bisector</u>

Step-by-step explanation:

A bisector is a line that divides a line segment in two equal parts. A perpendicular bisector is a line that is perpendicular to given line segment and passes through the mid-point of the line segment. It can also be said as that the line perpendicular to a line segment that divides the lines in half is called the perpendicular bisector.

The correct answer is:

A line that crosses segment at right angles while dividing the segment in half is called <u>a perpendicular bisector</u>

Keywords: Perpendicular, bisector

Learn more about geometry at:

#LearnwithBrainly

8 0

2 years ago