ShmoopTube

Where Monty Python meets your 10th grade teacher.

Search Thousands of Shmoop Videos


Geometry Videos 251 videos

Surface Area of Cylinders
14741 Views

Haven't you always wondered how much cardboard it takes to encase a trunk warmer for your pet elephant?

Perimeter of Irregular Shapes
4864 Views

Want to figure out the area and perimeter of irregular shapes? Break them down into regular shapes. For example, a flower can be broken down into s...

Introduction to 3D Geometry
55503 Views

It's one thing when all those shapes are sitting flat on the page. But when they start popping out and invading our personal space bubble, we get a...

See All

SAT Math 11.2 Geometry and Measurement 178 Views


Share It!


Description:

SAT Math 11.2 Geometry and Measurement


Transcript

00:02

Here’s your shmoop du jour, brought to you by translated lines.

00:06

Sometimes they're even foggier than Blurred Lines.

00:10

The line y = -2x + 4 is reflected over the y-axis, then translated down one unit and right two units.

00:18

What is its new y-intercept?

00:23

All right, so we’re talking about a line… on a graph…

00:25

The line in question is y = -2x + 4.

00:28

Here’s our graph. Now…where would that line go?

00:32

Well, if y is zero, then x would have to be 2… so let’s draw a point on the x axis at (2,0).

00:39

If we want x to be zero…it would create a point of intersection at the y-axis at (0,4).

00:44

So…la la la… connecting the dots…

00:46

And…there’s our line.

00:48

Now…what does this problem want us to do with it?

00:51

Cast it into a lake and see if we can catch ourselves a trout?

00:54

Uh, no. Wrong kinda line. First it wants us to REFLECT the line across the y-axis.

01:00

Well, one point is right ON the y-axis, so… that guy ain’t goin’ nowhere.

01:04

In fact, the entire line is pretty much just going to pivot around that point, sorta like a hinge.

01:10

What about our other point, the one at (2,0)?

01:13

Yeah, that one gets reflected across, and becomes (-2,0).

01:16

So our new line looks like this: Last step… we need to translate… or shift…

01:21

the line down one unit, and two to the right.

01:24

This time we move both points…like so…

01:27

…and there’s our line’s final resting place.

01:29

So…where’s the new y-intercept?

01:31

Right here… at negative 1. And we have our answer.

Related Videos

SAT Math 2.1 Geometry and Measurement
2779 Views

SAT Math 2.1 Geometry and Measurement. What is the measure of angle z in terms of x and y?

SAT Math 9.4 Algebra and Functions
1300 Views

SAT Math 9.4 Algebra and Functions

SAT Math 9.2 Algebra and Functions
377 Views

SAT Math 9.2 Algebra and Functions

SAT Math: Identifying an Equation for the Average of Two Percentages
23 Views

In 2014, the unemployment rate of one county in California was 7%. In another county, the unemployment rate was 11%. Which of the following express...

SAT Math: Which Equation Represents Profit?
13 Views

Angela is making cookies for a bake sale. She expects each batch of her cookies to sell for $40. It costs her $10 to make one batch of cookies, and...