Tutor profile: Sanjita G.
How can I know if there is a phase shift for a sin graph?
First of all, it is most important to understand what a phase shift is. A phase shift is how far the function is horizontal to the right of the usual position.The graph of an equation with a phase shift can be either stretched horizontally, moved horizontally, or stretched and moved horizontally. If the equation for a parabola is y = A sin(Bx + C) + D, B represents how horizontally stretched the graph is/ how fast it is moving and C represents how many unit positions it is moved to the right. Therefore, if the graph is both stretched and moved, the overall phase shift can be defined as -C/B. The negative is important because a negative phase shift indicates that the graph is moved to the right and a positive one indicates that the graph is moved to the left. Here is an example: If the equation is y=sin(2x+2), this means that from the original sin graph (y=sin(x)), the shifted one is 2 times faster (the graph crosses the x-axis 4 times between 0 and 1 instead of the 2 times that it does in the original sin graph). It also means that the graph is shifted 2 units to the left. Remember, when the argument (what is inside the parentheses) has a positive sign (i.e. (x+2)), this means move left, and when it has a negative sign (i.e. (x-2)), this means move right.
How can I analyze a literary piece of symbolism?
Often many literary pieces of the same style (i.e. Western literature) follow similar themes in regards to symbolism. For instance, the use of light often symbolizes reason or knowledge and the season of Spring often symbolizes rebirth or awakening. By knowing the symbolic meaning of a few commonly used topics, you can easily analyze any literary piece. By reading many literary pieces, you can start to determine these on your own but there are also some credible resources online that have summarized these common symbols. I found this resource to be helpful: http://www.learnstrong.co/uploads/5/3/9/2/53925379/symbols.pdf
What are there two types of nucleotides in DNA and how can I remember them?
The two types of nucleotides which compose DNA are purines and pyrimidines. Just to ensure that we have all our background knowledge solid, a nucleotide is composed of a five-carbon sugar, phosphate group, and nitrogenous base. Purines and pyrimidines are the two types of nitrogenous bases that can be attached to a sugar-phosphate backbone. Purines have a two ring structure, whereas pyrimidines have a one ring structure. The difference in structure causes different physical and chemical properties of the two. For instance, purines have higher melting and boiling points because of their larger structure. The way that I was taught to remember the difference between purines and pyrimidines and which nitrogenous bases were apart of each category was through the following pneumonic: If you want you agriculture (AG - Adenine, Guanine) to grow LARGE, you feed them Purina food (Purine). Therefore, the other nitrogenous bases not mentioned above (Uracil, Cytosine, and Thymine) are pyrimidines.
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