Answer:
New avaerage if 2 students (15 year old) left = 13
Step-by-step explanation:
Given:
Average age of 20 students = 13.2
Find:
New avaerage if 2 students (15 year old) left
Computtaion:
Sum of all 20 student's age = 20 x 13.2
Sum of all 20 student's age = 264
Sum of current 18 student's age = 264 - 15 - 15
Sum of current 18 student's age = 234
New avaerage if 2 students (15 year old) left = 234 / 18
New avaerage if 2 students (15 year old) left = 13
Answer:
D.
Step-by-step explanation:
0.72 = 72%
So that being the case, his car's value decreased by 72%
Answer:b
Step-by-step explanation:
This is the missing equation that models the hieght and is misssing in the question:
<span>h= 7cos(π/3 t)
</span>
Answers:
<span>a. Solve the equation for t.
</span>
<span>1) Start: h= 7cos(π/3 t)
</span>
2) Divide by 7: (h/7) = <span>cos(π/3 t)
</span>
3) Inverse function: arc cos (h/7) = π/3 t
4) t = 3 arccos(h/7) / π ← answer of part (a)
b. Find the times at which the weight is first at a height of 1 cm, of 3
cm, and of 5 cm above the rest position. Round your answers to the
nearest hundredth.
<span>1) h = 1 cm ⇒ t = 3 arccos(1/7) / π</span>
t = 1.36 s← answer
2) h = 3 cm ⇒ t = 3arccos (3/7) / π = 1.08s← answer
3) h = 5 cm ⇒ 3arccos (5/7) / π = 0.74 s← answer
c. Find the times at which the weight is at a height of 1 cm, of 3 cm, and of 5 cm below the rest position for the second time.
Use the periodicity property of the function.
The periodicity of <span>cos(π/3 t) is 6.
</span><span>
</span><span>
</span><span>So, the second times are:
</span><span>
</span><span>
</span><span>1) h = 1 cm, t = 6 + 0.45 s = 6.45 s ← answer
</span>
2) h = 3 cm ⇒ 6 + 1.08 s = 7.08 s← answer
3) h = 5 cm ⇒ t = 6 + 0.74 s = 6.74 s ← answer
Answer:
Step-by-step explanation:
The quadratic formula states that the solutions for a quadratic is standard form 
are equal to 
.
In 
, we can assign the values:
Thus, we have:
of 5
of -2
of -8