The first four terms are -6, -7, -9 and -13.
Step-by-step explanation:
- Step 1: Given first term, a(1) = -6 and the nth term, a(n) = 2a(n-1) + 5. FInd the first four terms.
⇒ a(1) = -6
⇒ a(2) = 2a(1) + 5 = 2 × -6 + 5 = -12 + 5 = -7
⇒ a(3) = 2a(2) + 5 = 2 × -7 + 5 = -14 + 5 = -9
⇒ a(4) = 2a(3) + 5 = 2 × -9 + 5 = -18 + 5 = -13
Answer:
![A = 52](https://tex.z-dn.net/?f=A%20%3D%2052)
Step-by-step explanation:
Given
![A = 14 + B](https://tex.z-dn.net/?f=A%20%3D%2014%20%2B%20B)
Required
Find A
Since both angles are complementary; then:
![A + B = 90](https://tex.z-dn.net/?f=A%20%2B%20B%20%3D%2090)
Solve for B in ![A = 14 + B](https://tex.z-dn.net/?f=A%20%3D%2014%20%2B%20B)
![B = A - 14](https://tex.z-dn.net/?f=B%20%3D%20A%20-%2014)
Substitute
in ![A + B = 90](https://tex.z-dn.net/?f=A%20%2B%20B%20%3D%2090)
![A + A - 14 = 90](https://tex.z-dn.net/?f=A%20%2B%20A%20-%2014%20%3D%2090)
![2A - 14 = 90](https://tex.z-dn.net/?f=2A%20-%2014%20%3D%2090)
Solve for 2A
![2A = 90 + 14](https://tex.z-dn.net/?f=2A%20%3D%2090%20%2B%2014)
![2A = 104](https://tex.z-dn.net/?f=2A%20%3D%20104)
Solve for A
![A = 104/2](https://tex.z-dn.net/?f=A%20%3D%20104%2F2)
![A = 52](https://tex.z-dn.net/?f=A%20%3D%2052)
The Surface area of the whole cone is 4408.56 cm²
The Surface area of the tips that is removed is 376.8 cm²
The Surface area of the megaphone(hollow) is 2712.96 cm²
<h3 /><h3>What is surface area?</h3>
Surface area is the sum of the areas of all faces (or surfaces) on a 3D shape.
Therefore,
Surface area of the whole cone = πr² + πrl
Therefore,
Surface area of the whole cone = πr(r + l)
where
- r = radius = 18 cm
- l = edge length = 60 cm
Surface area of the whole cone = 3.14 × 18(18 + 60) = 4408.56 cm²
Surface area of the tips that is removed = 3.14 × 4 (18 + 12) = 376.8 cm²
Surface area of the megaphone(hollow) = πrl
Surface area of the megaphone(hollow) = 3.14 × 18 × (60 - 12) = 2712.96 cm²
learn more on surface area here: brainly.com/question/7410402