Pharmaceutical companies prefers experimental studies to conducting surveys and observational studies because companies can manipulate or suggest methods easily to have good outcomes and they are able to directly observe the results. Experimental studies is a type of study in which a procedure and method is intentionally introduced.
A
using the Cosine rule in ΔSTU
let t = SU, s = TU and u = ST, then
t² = u² + s² - (2us cos T )
substitute the appropriate values into the formula
t² = 5² + 9² - (2 × 5 × 9 × cos68° )
= 25 + 81 - 90cos68°
= 106 - 33.71 = 72.29
⇒ t = 
≈ 8.5 in → A
Answer:
See below.
Step-by-step explanation:
Since sqrt(a) and sqrt(b) are in simplest radical form, that means a and b have no perfect square factors. When sqrt(a) and sqrt(b) are multiplied giving c * sqrt(d), the fact that c came out of the root means that there was c^2 inside the product sqrt(ab). This means that a and b have at least one common factor.
ab = c^2d
Example:
Let a = 6 and let b = 10.
sqrt(6) and sqrt(10) are in simplest radical form.
Now we multiply the radicals.
sqrt(a) * sqrt(b) = sqrt(6) * sqrt(10) = sqrt(60) = sqrt(4 * 15) = 2sqrt(15)
We have c = 2 and d = 15.
ab = c^2d
6 * 10 = 2^2 * 15
60 = 60
Our relationship between a, b and c, d works.
