Answer:
360
Step-by-step explanation:
A circle has 360 degrees.
Here lesson started at 9 and finished at 10.
This means that her lesson was one hour.
A minute hand makes a full rotation in an hour.
It would have started at 12, and ended back at 12.
This means that it rotated 360 degrees.
Question:
Prove that:

Answer:
Proved
Step-by-step explanation:
Given

Required
Prove

Subtract tan(10) from both sides


Factorize the right hand size

Rewrite as:

Divide both sides by 


In trigonometry:

So:
can be expressed as: 
gives


In trigonometry:

So:

Because RHS = LHS
Then:
has been proven
Answer:
x = ±2√10
Step-by-step explanation:
40 - x² = 0
⇌
(√40 - x)(√40 + x) = 0
⇌
x = √40 or x = -√40
we can go further and say that √40 = 2√10
If certain refrigerator requires 170 watts of electricity when it is running. It typically runs about 20 minutes per hour. The amount it cost to run this refrigerator for one year if the cost per kWh is $0.11 is: $53.856.
<h3>Cost</h3>
Given:
Electricity watts = 170 watts
Minutes run = 20 minutes
Cost per KWh =$0.11
Hence,
170 watts = 1.7×10^-1
20 min = 1/3 h
Now let calculate the cost of running the refrigerator for one year
1.7×10^-1 × 1/3 × 24 ×360 × $0.11
= $53.856
Therefore If certain refrigerator requires 170 watts of electricity when it is running. It typically runs about 20 minutes per hour. The amount it cost to run this refrigerator for one year if the cost per kWh is $0.11 is: $53.856.
Learn more about watts here: brainly.com/question/25781540
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Answer:
a c
Step-by-step explanation: