Answer:
364.5
Step-by-step explanation:
you would need a calculator for it, unless you can do exponential math at such a degree... if you're using a PC there's a good graphing calculator at Desmos.com, it can show you how a graph looks, which shows that when n is 7, the answer is 364.5. also it wouldn't be 1093.5 because the exponent is n-1 which means that while n could be 7, you need to take away 1 before using it as an exponent.
The correct answer is C. F(x)=2 * (0.7)^x
So there is an identity we'll need to use to solve this:
cos(x+y) = cosxcosy - sinxsiny
replace the numerator with the right hand side of that identity and we get:
(cosxcosy - sinxsiny)/cosxsiny
Separate the numerator into 2 fractions and we get:
cosxcosycosxsiny- sinxsiny/cosxsiny
the cosx's cancel on the left fraction, the siny's cancel on the right fraction and we're left with:
cosy/siny - sinx/cosx
which simplifies to:
coty - tanx
Answer :
27.5 minutes
Steps:
1) put into fraction form:
160/20 = 220/x
2) simplify:
160/20 = 8/1
3) cross multiply:
8 • x = 8x
220 • 1 = 220
4) divide on both sides:
8/8 = crosses out
220/8 = 27.5
