Answer:
Step-by-step explanation:
We are to show that 
<u>Proof:</u>
From trigonometry identity;


From trigonometry, 2sinAcosA = Sin2A

Also note that sin(B-C) = sinBcosC - cosBsinC
sin420cos140 - cos420sin140 = sin(420-140)
The resulting equation becomes;

= 
Answer:
It will take 36.1 years for her money to reach $105,000.
Step-by-step explanation:
The amount of money earned after t years in continuous interest is given by:

In which P(0) is the initial investment and r is the interest rate, as a decimal.
Anna invests $7,000 in an account that compounds interest continuously and earns 7.5%.
This means that 
How long will it take for her money to reach $105,000?
This is t for which P(t) = 105000.








It will take 36.1 years for her money to reach $105,000.
Answer:
5.208 lbs
Step-by-step explanation:
12.4 lbs times 0.42 is 5.208 lbs
it is simple
It would take 328 seconds or 5 minutes and 47 seconds