# Tutor profile: Christina V.

## Questions

### Subject: Greek

Write the Nominative, Genitive, Accusative, and Vocative versions of the name Nick.

Nominative: O Nikos Genitive: Tou Nikou Accusative: To Niko Vocative: Niko Nominative is used when the noun is the subject of the sentence. For example, O Nikos exei duo skulakia. Ο Νίκος έχει δύο σκυλάκια, or Nick has two puppies. Genitive is used for possessive nouns. For example, Ta duo skulakia einai tou Nikou. Τα δύο σκυλάκια είναι του Nίκου, or The two dogs are Nick's. Accusative is used when answering the question whom? or what? A noun in the accusative will be the direct object in a sentence. For example, Auth fwnazei to Niko. Αυτή φωνάζει το Niko. She yells to Nick. Vocative is used when calling someone. For example, Niko! To vradino einai etoimo. Nίκο! Το βραδινό είναι έτοιμo. Nick! Dinner is ready.

### Subject: Physics (Heat Transfer)

What is the difference between heat and temperature?

Temperature is a metric which we use to describe the relative thermal energy that something contains. Heat, on the other hand, IS thermal energy. The amount of heat or thermal energy that an object contains determines its temperature. Two objects may have the same thermal energy, but different temperatures, and vice versa. This is due to the fact that thermal energy depends on the material of an object, as well as the size/mass. What is the y-intercept of the following function?

### Subject: Algebra

What is the y-intercept of the following function? (y-x)^2=81

We can solve this in two ways. Method #1. In this case, our function is a line, because the variables y and x are to the first power (y^1 and x^1). We know that the y-intercept of any function is the vertical location at which the function INTERCEPTS the y-axis, or where it crosses the vertical axis. At the vertical axis (or y-axis), x equals 0. Let's set x=0 in the equation. (y-x)^2 => (y-0)^2 => (y)^2 = 81 To solve for y, which will give you the y-intercept, take the square root of both sides of the equation. The square root of y^2 equals y, and the square root of 81 is 9. Therefore, y=9, where y is your y-intercept. Method #2. We know b is the y-intercept when an equation takes this form: y=mx+b. Let's get the equation to look like this. We can first start by taking the square root of both sides again, which will give us y-x=9. This almost looks like it's in the correct form, but we need to move the x to the right side of the equals sign. To do so, we have to add x to each side. We then have y-x+x=9+x. We know that -x+x=0; therefore y=9+x=x+9. It's finally in the correct form! Because b (from y=mx+b) represents any number (not variable) on that side of the equation, we know that b=9 in our equation and that 9 is the y-intercept.

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