6 ft equals 72 inches or 1.829 meters
Hmmm, as I read it, in year 1, but it doesn't say at the beginning of the year or end, so we'll be assuming is at the beginning of year 1, the amount is 850, how much will it be at the beginning of year 6? namely, 5 years later.
To figure out if a graph is a function, you can use this thing called the vertical line test. in case you're unfamiliar, it's basically where you just imagine a vertical line going from left to right on the graph. if it crosses the function in two places, it's incorrect. i suggest looking up a video that shows you a visual representation of the vertical line test if you've never heard of it; it's fairly simple.
A is a function because the graph passes the vertical line test. if you imagine a vertical line and drag it from left to right across the graph, the linear function graphed in choice A does not have two x values at the same spot.
B is not a function. it fails the vertical line test almost immediately: the sideways "U" shapes makes it intersect the vertical line twice in one place.
C is a function. it passes the vertical line test, even though it looks a little strange. at no point does it intersect the vertical line twice.
D is a function. again, it doesn't intersect the vertical line twice.
now, to determine if a function is a one-to-one function, it must also pass the horizontal line test. this means that it doesn't intersect at two points horizontally as well. test that out on choices A, C, and D.
A is a one-to-one function because it doesn't cross in the same place horizontally, either. C and D are one-to-one functions as well.
Cofunctions in trigonometry are function pairs like sine and cosine
Examples:
sin(π/2 - x) = cos(x), cos(π/2 - x) = sin(x), tan(π/2 - x) = cot(x), and cot(π/2 - x) = tan(x)
Purpose:
The cofunction identities show the relationship between sine, cosine, tangent, cotangent, secant, and cosecant. The value of an angle's trig function equals the value of the angle's complement's cofunction

so in short, the only factoring doable to it, without any complex factors, is that of taking the common factor of 2x.
now, the trinomial of 2x²+x+1, will not give us any "real roots", just complex or "imaginary" ones.
if you have already covered the quadratic formula, you could test with that, or you can also check that trinomial's discriminant, and notice that it will give you a negative value.