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### Course: Algebra 1 (Eureka Math/EngageNY)>Unit 4

Lesson 14: Topic C: Lessons 20-22: Scaling and transforming graphs

# Graphs of square-root functions

Sal graphs y=√x. Then, he shows a few examples of how we can shift and stretch the graphs of y=√x and y=x^2, and how the equations of those graphs look. Created by Sal Khan and CK-12 Foundation.

## Want to join the conversation?

• If you still don't understand these types of equations, what video would you recommend to help you understand it?
• So Does That Mean That 9 Is The Square Root Of 81?
(1 vote)
• yes because 9x9=81
• In , how would you be able to read the graph to find the horizontal and vertical stretch and compression without knowing the equations of the sq. rt functions beforehand?
• how can negative numbers be square roots
• There are two ways to get to the square root of a number like 9:
3 * 3 = 9 (positive or principal root)
-3 * -3 = 9 (negative)
You need to add a negative sign in front of the square root symbol if you want the negative square root as the answer so - square root of 9 is -3.
• how would I explain to my daughter on the following problem: f(x) = 1/9 x -8=
• Just say no matter what x is, f(x) is one-ninth of x minus 8
• How can a graph be drawn when there is a negative radicand? Is that not an imaginary expression?
• If you have to both shift and to stretch (increase, or decrease the amplitude) a function which one of the two procedures has precedence? As far as i'm concerned stretching the function should take place first. But, i'm not sure. Help?
• You can do it any way you want, but if you don't use parenthesis to specify, then the stretch will take precedence (because in order of operations multiplication/division comes before addition/subtraction).
(1 vote)
• What about y = x (square root) 2
(1 vote)
• If you mean y = x sqrt(2) , then its a linear equation passing through the origin (0,0) with sqrt(2) as the slope.