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## Pixar in a Box

### Course: Pixar in a Box>Unit 11

Lesson 2: Calculating parabolas

# 2. Where is the touching point?

Where does the string touch the parabola? See if you can come up with your hypothesis!

## Want to join the conversation?

• what would the touching place be for
• The touching place is to see at what point on the parabola, the straight line is tangent with the parabola. For the computer, this is useful to know whether or not to place a pixel (color) at that exact location.
• i a work as a security guard at samsung, am i a Guardian of the galaxy??/? /LORD HELP MEEEE
• I have a question about the next exercise 'Exploring the parabola construction'. What do they mean when they indicate a line like this: AQ|AB = QB|AB (in the normal question, these are written underneath each other)?

• AQ / AB means the ratio of the length of AQ : AB. In other words it's a fraction - you divide the length of AQ by the length of AB.
• i have no idea what is going on
• When do i get to make a cartoon
(1 vote)
• Making cartoons take lots of coordination. Many shorts even take 100+ people! But it is possible.
• how do you get the weight
(1 vote)
• The weight, the t value from the previous lesson, is whatever you need it to be. It's the variable in the equation. The only rule is that it has to be between 0 and 1. When you plug every possible value for t into the ultimate formula that will be constructed, then you'll get all of the possible touching points. Graphing all of those points (or an evenly-distributed finite set of them, at any rate) will create the parabolic arc.

In short, you don't "get" the weight. You provide the weight.