Recall the sum identity for cosine:
cos(a + b) = cos(a) cos(b) - sin(a) sin(b)
so that
cos(a + b) = 12/13 cos(a) - 8/17 sin(b)
Since both a and b terminate in the first quadrant, we know that both cos(a) and sin(b) are positive. Then using the Pythagorean identity,
cos²(a) + sin²(a) = 1 ⇒ cos(a) = √(1 - sin²(a)) = 15/17
cos²(b) + sin²(b) = 1 ⇒ sin(b) = √(1 - cos²(b)) = 5/13
Then
cos(a + b) = 12/13 • 15/17 - 8/17 • 5/13 = 140/221
Answer:
Step-by-step explanation:
Let's start off with the first equation
5x + y = 60
We need to find what X and Y are.
Let's try subtracting a few numbers from 60.
Let's do 60 - 55 = 5
11x5 = 55
11 = Children Ticket Cost
5 = Seniors Ticket Cost
Without them being the same price!
So using the numbers we found, we can now solve the second one
14x5 = 70
11x11 = 121
70 + 121 = 191
There we go!
Hope this helped! Please give brainiest if you can :)
Answer:
The correct answer: F (Scalene) and A (Acute)
Step-by-step explanation:
F. (Scalene): By definition, a scalene triangle is a triangle that has no equal sides, and no equal angles. This definition matches your given triangle, since it has no equal sides and angles.
A. (Acute): By definition, an acute triangle is a triangle in which all the internal angles are less than 90 degrees. This definition matches your given triangle, since all of the internal angles are less than 90 degrees.
The given triangle is not obtuse, equilateral, right, and isoceles.
It is <u>not</u> an <em>obtuse </em>triangle because none of the angles are greater than 90 degrees.
It is <u>not</u> an <em>equilateral</em> triangle because its sides are not equal.
It is <u>not</u> a <em>right</em> triangle because none of its internal angles measure 90 degrees.
And it is <u>not</u> an <em>isoceles</em> triangle because by definition, an isoceles triangle must have two equal sides. Your given triangle has no equal sides.
I’m RIGHT here how can I help, there is no photo.
