Option A

<em><u>Solution:</u></em>
Given that we have to rewrite with only sin x and cos x
Given is cos 3x

We know that,

Therefore,
---- eqn 1
We know that,


Substituting these values in eqn 1
-------- eqn 2
We know that,

Applying this in above eqn 2, we get



Therefore,

Option A is correct
It would take .25 gallon (or 1/4 gallon) to drive 9 1/4 mile.
I guess that's all you can do
to find a and b you need more information
b=-a -> a (x-3)-a (x-2)=3
a [x-3-(x-2)]=3
a (x-3-x+2)=3
a*(-1)=3
a=3:(-1)
a=-3
b=-a=-(-3)=3
just do 2.80-0.75 and you'll get your original which is 2.05 for the 2nd past
for the 1st one I'd do 2.80 divided by 0.75 and I would get 37 cents