
That's vertex form for a parabola
and we read off vertex (p,q) as
Answer: Vertex (5,7)
The negative <em>a</em> tells us this is a downward opening parabola (upside down from the usual
. I remember CUP - Concave Up Positive; here <em>a </em>is negative so not a cup, instead concave <em>down.</em> The same rule applies to second derivatives in calculus so memorize it now and use it later.
Answer: downward
Answer:The crystal structures of five 6-mercaptopurine derivatives, viz. 2-[(9-acetyl-9H-purin-6-yl)sulfanyl]-1-(3-methoxyphenyl)ethan-1-one (1), C16H14N4O3S, 2-[(9-acetyl-9H-purin-6-yl)sulfanyl]-1-(4-methoxyphenyl)ethan-1-one (2), C16H14N4O3S, 2-[(9-acetyl-9H-purin-6-yl)sulfanyl]-1-(4-chlorophenyl)ethan-1-one (3), C15H11ClN4O2S, 2-[(9-acetyl-9H-purin-6-yl)sulfanyl]-1-(4-bromophenyl)ethan-1-one (4), C15H11BrN4O2S, and 1-(3-methoxyphenyl)-2-[(9H-purin-6-yl)sulfanyl]ethan-1-one (5), C14H12N4O2S. Compounds (2), (3) and (4) are isomorphous and accordingly their molecular and supramolecular structures are similar. An analysis of the dihedral angles between the purine and exocyclic phenyl rings show that the molecules of (1) and (5) are essentially planar but that in the case of the three isomorphous compounds (2), (3) and (4), these rings are twisted by a dihedral angle of approximately 38°. With the exception of (1) all molecules are linked by weak C—H⋯O hydrogen bonds in their crystals. There is π–π stacking in all compounds. A Cambridge Structural Database search revealed the existence of 11 deposited compounds containing the 1-phenyl-2-sulfanylethanone scaffold; of these, only eight have a cyclic ring as substituent, the majority of these being heterocycles.
Keywords: crystal structure, mercaptopurines, supramolecular structure
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Chemical context
Purines, purine nucleosides and their analogs, are nitrogen-containing heterocycles ubiquitous in nature and present in biological systems like man, plants and marine organisms (Legraverend, 2008 ▸). These types of heterocycles take part of the core structure of guanine and adenine in nucleic acids (DNA and RNA) being involved in diverse in vivo catabolic and anabolic metabolic pathways.
6-Mercaptopurine is a water insoluble purine analogue, which attracted attention due to its antitumor and immunosuppressive properties. The drug is used, among others, in the treatment of rheumathologic disorders, cancer and prevent
Step-by-step explanation:
SOH CAH TOA
—>
Sin D = 13 sqrt3/26 = 0.76
Sin E = 13/26 = 0.47
Cos D = 13/26 = 0.87
Cos E = 13 sqrt3/26 = 0.64
Answer:
A. 183 meters
Step-by-step explanation:
Building A and building B are 500 meters apart. There is no road between them, so to drive from building A to building B, it is necessary to first drive to building C and then to building B. About how much farther is it to drive than to walk directly from building A to building B? Round to the nearest whole number. A) 183 meters B) 250 meters C) 366 meters D) 683 meters
Find distance BC
Cos (60°)=BC / AB (Adjacent divided by the hypotenuse)
Cos (60°)=1/2
BC=a
AB=500
Cos (60°)=BC / AB
1/2=a/500
1/2 * 500=a
250=a
a=250m
Find distance AC
Sin(60°)=AC/AB (opposite side divided by hypotenuse)
Sin(60°)=√3/2
AC=b
AB=500
Sin(60°)=AC/AB
√3/2=b/500
√3/2 * 500=b
250√3=b
b=433m
Distance AC and BC=AC+BC
433m+250m=683m
Subtract the distance AB from AC+BC
= 683m - 500m
=183m
Answer is A. 183 meters
Answer:
D. 2058.24 in³
Step-by-step explanation:
Let r,h be the radius and height of smaller can and R,H be the radius and height of larger can
Then, R=4r and H=4h
Volume of smaller can=32.16 in³
⇒ πr²h=32.16 in³
Volume of larger can= πR²H
= π(4r²)×4h
= 64πr²h
= 64×32.16 in³
= 2058.24 in³
Hence, correct option is:
D. 2058.24 in³