For the answer to the question above,
<span>Let's work with the left-hand side
We're going to times cosx/1-sinx by 1+sinx/1+sinx, you can do this because 1+sinx/1+sinx is equal to 1, so you aren't really changing anything.
After you've times the top and bottom by 1+sinx, you get:
cosx(1+sinx) / (1-sinx)(1+sinx)
The denominator is a difference of squares, so you get 1-sin^2 x
what you have now is
cosx(1+sinx) / 1-sin^2x
You know that 1-sin^2x is equal to cos^2x
so know you have
cosx(1+sinx) / cos^2x
get rid of the cosx on top by simplifying and the cos^2x so that you're left with
(1+sinx) / cos x
Therefore cosx / 1- sinx = 1 + sinx / cos x</span>
<span>The doubling time is the period of time
required for a quantity to double in size or value. It is applied to
population growth, inflation, resource extraction, consumption of goods,
compound interest, the volume of malignant tumours, and many other
things that tend to grow over time.</span>
(45 gal/day) x (31 day/Dec) =
(45 x 31) (gal/Dec) = <em>1395 gallons</em> per December .
Choice-B is closer to that figure than Choice-A is,
but they're both poor estimates.
These triangles are not congruent. They only have 2 sides and one angle in common, and that is not a congruency theorem.
