So basically you can determine which of them are functions by using the vertical line test. If you can draw any vertical line that intersects more than one point of the relationship, then it is not a function.
I'm not complete sure about the discrete one but, hopefully it's right :).
Wow! There so much extra stuff on this drawing, naturally it's hard to see
what's going on.
First, do you remember "vertical angles" ? They're the pair of opposite angles
that form where lines cross, and they're equal.
-- It says that angle-1 is 55 degrees.
Angle-1 and angle-7 are vertical angles, so angle-7 is also 55 degrees.
-- It says that angle-4 is 60 degrees.
Angle-4 and angle-6 are vertical angles, so angle-6 is also 60 degrees.
Now you can forget about all that stuff that's outside of the triangle in the middle,
and just look at the triangle. They want you to find angle-10.
See the angles at the top of the triangle ... angle-7 and angle-6 ?
We know what both of those are. Angle-7 is 55 degrees, and angle-6 is 60 degrees.
Do you remember what the 3 angles inside a triangle always add up to ?
They always add up to 180 degrees.
Add angle-7 and angle-6 together . . . 55 + 60 = 115 degrees.
So angle-10 is just the rest of the 180 degrees inside the triangle.
Angle-10 = 180 - (115) = 65 degrees
3.872 is equal to 3872/1000, or 484/125.
The answer is B. Use distance formula...
To solve this question, you need to know the rate in which the money is being spent. First, you know the y-intercept, which is 4000, or the money she owned before spending it. Next, you know, how much she had spent in the duration of 3 months. So, if you substitute those numbers into y=ax+b, it would be 2800=-3a+4000 (or 2800=4000-3a either way it is equivalent) If you solve this, you know that the college freshman is spending her money at a rate of $400 per month. Hope this helps :)