Answer:
50 Minutes.
Step-by-step explanation:
The function c approximates the total number of calls made after m minutes since the start of the phone tree.
![c(m)=\frac{2}{3}\times (3^{\frac{m}{10}}-1)](https://tex.z-dn.net/?f=c%28m%29%3D%5Cfrac%7B2%7D%7B3%7D%5Ctimes%20%283%5E%7B%5Cfrac%7Bm%7D%7B10%7D%7D-1%29)
We need to find the number of minutes after which the total number of calls will 363.
Substitute c(m)=363 in the given function.
![363=\frac{2}{3}\times (3^{\frac{m}{10}}-1)](https://tex.z-dn.net/?f=363%3D%5Cfrac%7B2%7D%7B3%7D%5Ctimes%20%283%5E%7B%5Cfrac%7Bm%7D%7B10%7D%7D-1%29)
Multiply 3/2 both sides.
![363\times \frac{3}{2}=(3^{\frac{m}{10}}-1)](https://tex.z-dn.net/?f=363%5Ctimes%20%5Cfrac%7B3%7D%7B2%7D%3D%283%5E%7B%5Cfrac%7Bm%7D%7B10%7D%7D-1%29)
![242=3^{\frac{m}{10}}-1](https://tex.z-dn.net/?f=242%3D3%5E%7B%5Cfrac%7Bm%7D%7B10%7D%7D-1)
Add 1 on both sides.
![243=3^{\frac{m}{10}}](https://tex.z-dn.net/?f=243%3D3%5E%7B%5Cfrac%7Bm%7D%7B10%7D%7D)
![3^5=3^{\frac{m}{10}}](https://tex.z-dn.net/?f=3%5E5%3D3%5E%7B%5Cfrac%7Bm%7D%7B10%7D%7D)
On comparing both sides we get
![5=\frac{m}{10}](https://tex.z-dn.net/?f=5%3D%5Cfrac%7Bm%7D%7B10%7D)
Multiply both sides by 10.
![50=m](https://tex.z-dn.net/?f=50%3Dm)
Therefore, the total number of calls will 363 after 50 minutes since the start of the phone tree.
Answer:
AB = 75
BC = 60
AC = 45
m∠A = 53°
m∠B = 37°
m∠C = 90°
Step-by-step explanation:
<u>Trigonometric ratios</u>
![\sf \sin(\theta)=\dfrac{O}{H}\quad\cos(\theta)=\dfrac{A}{H}\quad\tan(\theta)=\dfrac{O}{A}](https://tex.z-dn.net/?f=%5Csf%20%5Csin%28%5Ctheta%29%3D%5Cdfrac%7BO%7D%7BH%7D%5Cquad%5Ccos%28%5Ctheta%29%3D%5Cdfrac%7BA%7D%7BH%7D%5Cquad%5Ctan%28%5Ctheta%29%3D%5Cdfrac%7BO%7D%7BA%7D)
where:
is the angle- O is the side opposite the angle
- A is the side adjacent the angle
- H is the hypotenuse (the side opposite the right angle)
Given:
![\sf \tan(A)=\dfrac{60}{45}](https://tex.z-dn.net/?f=%5Csf%20%5Ctan%28A%29%3D%5Cdfrac%7B60%7D%7B45%7D)
Therefore:
- side opposite angle A = BC = 60
- side adjacent angle A = AC = 45
To find the length of AB (the hypotenuse), use Pythagoras’ Theorem:
![a^2+b^2=c^2](https://tex.z-dn.net/?f=a%5E2%2Bb%5E2%3Dc%5E2)
(where a and b are the legs, and c is the hypotenuse, of a right triangle)
⇒ AC² + BC² = AB²
⇒ 45² + 60² = AB²
⇒ AB² = 5625
⇒ AB = √5625
⇒ AB = 75
To find m∠A:
![\implies\sf \tan(A)=\dfrac{60}{45}](https://tex.z-dn.net/?f=%5Cimplies%5Csf%20%5Ctan%28A%29%3D%5Cdfrac%7B60%7D%7B45%7D)
![\implies\sf A=\tan^{-1}\left(\dfrac{60}{45}\right)](https://tex.z-dn.net/?f=%5Cimplies%5Csf%20A%3D%5Ctan%5E%7B-1%7D%5Cleft%28%5Cdfrac%7B60%7D%7B45%7D%5Cright%29)
![\implies\sf A=53^{\circ}\:(nearest\:degree)](https://tex.z-dn.net/?f=%5Cimplies%5Csf%20A%3D53%5E%7B%5Ccirc%7D%5C%3A%28nearest%5C%3Adegree%29)
m∠C = 90° (as it is a right angle)
The interior angles of a triangle sum to 180°
⇒ m∠A + m∠B + m∠C = 180°
⇒ 53° + m∠B + 90° = 180°
⇒ m∠B = 180° - 53° - 90°
⇒ m∠B = 37°
T = -20 so
t+1= -20 + 1
= -19
Answer: 5.64 *10^2
Step-by-step explanation:
<h3>
2 Answers: B and D</h3>
===================================================
Explanation:
Choice B is one answer because -2 and 2 are additive inverses that add to -2+2 = 0
Choice D is a similar story. We have -5+5 = 0
In general, if x is some number then -x is its additive inverse. So we can say x+(-x) = 0 or -x+x = 0. In short, additive inverses add to 0.