How to Write a Function From a Graph

Next Video:
Grade 5 Math: Comparing Whole Numbers....5

Writing a function from a graph will require you to look at the power of X. Write a function from a graph with help from a professional private tutor in this free video clip.

Part of the Video Series: Math Made Easy
Promoted By Zergnet


Video Transcript

Hi, I'm Rachel, and today we're going to be going over how to write a function from a graph. There are a few things you want to look for when you are looking at the graph in order to derive the function. The first thing is you're going to want to look for the power of X. If it's X to the first, the graph is going to be going in one direction, right, like one line. If it's X to the second, the graph is going to be going in two directions. If it's X to the third, the graph will be going in three directions and so on. You are also going to want to look to see if it's a positive or negative slope. For example if you start from left to right like you are reading, this is the positive slope, you can think of if there's a little man who wants to like you know, walk up he can walk up the hill, right, it's a positive slope but, if you have a line like this on a graph, the little man comes over, he can't walk up that right, he has to rock climb up a negative incline which is a lot more difficult. This is a negative slope. That's a positive slope, that's how you can tell. With a parabola, right, this quadratic equation that goes in two directions, it's a positive slope if it makes a smiley face. It's a negative slope if it makes a frowny face like that. You are also going to want to look for the Y intercept where the line crosses the Y axis on the graph. You are also going to want to look at the slope. The slope is the rise over the run. Is it a steep slope, right, something that you know is going to be really hard to hike up or is it a gradual slope, something that's going to be easy? Is it, you know with the steep parabola, it's going to be something like this, right, whereas a you know, not so big of a slope right like maybe more like one half it's going to be more of a gradual parabola. I'm Rachel and thanks for learning with us today.


Related Searches

Is DIY in your DNA? Become part of our maker community.
Submit Your Work!