Tutor profile: Jacquie D.
Subject: Basic Math
Solve the following equation using the quadratic formula: x^2 + 5x + 6 = 0
Recall that the quadratic formula is as follows: x = [-b +/- (b^2 - 4(a)(c))^0.5] / 2(a) Note: raising something to the power of 1/2 is the same as taking its square root (it is harder to type a square root!) The first thing we have to do is identify the variables a, b and c in this equation. In any quadratic formula - that means an equation with a variable squared - it is easy to determine which number goes with which variable. "a" is the coefficient - or number - before the x^2. "b" is the coefficient before the x. "c" is the number that is left without an "x" next to it. So, in this problem, we can start out by saying that: a = 1 b = 5 c = 6 Note: since there is no coefficient before the x^2, we say that it is 1. The next thing we do is plug in all of our variables into the quadratic formula: x = [-(5) +/- (5^2 - 4(1)6))^0.5] / 2(1) = [-5 +/- (25 - 24)^0.5] / 2 Note: at this point we have to split the equation in 2 because the +/- sign means the answer will be correct is we add OR subtract. Starting with adding: x = -5 + 1 / 2 = -2 Now with subtracting: x = -5 - 1 / 2 = -3 Finally, we have come to the conclusion that x = -5 and x = -3
An important part of a cell is the outer layer called the phospholipid bilayer. What is the role of this component and how does it accomplish it?
The phospholipid bilayer has the job of controlling what can get in and out of the cell. In other words, it controls the PERMEABILITY of the cell. It is important for cells to be able to select what comes in and out in order to maintain homeostasis. The bilayer is made of 2 layers of phospholipids (fats) which each have a hydrophobic tail facing in and a hydrophilic head facing out. This is important as it allows the cell to control which molecules can get through. For example, water CANNOT get through the bilayer because the hydrophobic tails don't let it through. This is good because it means that too much water can't get in to burst the cell and at the same time, water can't freely exit which would cause the cell to shrivel. Instead, the cell develops specials passages - channels - for water to go through so that it can carefully control the passage.
Describe the pathway of blood from the heart to the lungs and body and then back.
We start out by understanding that deoxygenated blood flows through the heart, gets ejected to the lungs to become oxygenated and then the oxygenated blood is sent back to the heart in order to be sent to the body. Now we have a basic pathway that we can follow and we just have to add in some details. Blood from the body comes in through the superior and inferior vena cava and travels through the RIGHT side of the heart. (remember, in anatomical position, the right side of the body is what we see on the left side of an image!) The heart has 4 chambers, 2 on each side, and the first chamber the blood enters (think of it as the entrance room) is the ATRIUM. So, blood goes through the IVC to the RIGHT ATRIUM. Next, it goes to the RIGHT VENTRICLE. Next, we know it has to go to the lungs and it goes through a tube called the pulmonary artery. Now the blood has to come back to the LEFT side of the heart. It comes through a tube called the pulmonary vein into the LEFT ATRIUM. Just like on the right side, the next chamber is the LEFT VENTRICLE. Finally, the blood needs to leave the heart to go to the body and it exits through a tube called the AORTA.
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