## sadiebee123 one year ago Can someone please explain this to me?? Write an equation for the following transformation of y=x: a vertical stretch by a factor of 4

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1. jdoe0001

y = A ( Bx + C ) + D A = vertical stretch thus if the "parent function" is $$\bf y = x$$ the "transformed function" is $$\bf y = \color{red}{4}x$$

2. jdoe0001

transformed just means, the parent function, or a basic barebones function, with PADDED WITH EXTRA STUFF AROUND

I just don't understand :c

4. jdoe0001

a parent function is just usually a barebone variable expression

What does that mean?... I'm sorry I'm really terrible at math, it's not my cup of tea. I do a lot better when people explain things step by step..

6. jdoe0001

|dw:1380828836174:dw|

7. jdoe0001

as you PAD MORE STUFF to the written function, the graph moves about or "shifts" or "translates" about

8. jdoe0001

in the case above, I use vertical and horizontal "transformation", in your case for the exercise given, you just need a vertical stretch, that means a multiplier in front of it = A ( Bx + C ) + D A = vertical stretch C = horizontal shift D = vertical shift

Oh okay, but how do I get a whole equation like that out of only y=x and 4?

10. jdoe0001

hmmm,... check above, my 1st line

So I don't need all that extra C and D stuff?

12. jdoe0001

right, you don't the A, B, C, D components are for transformations of different kinds, you should know about, in this case, you only needed A, or the one in front of the function

Ohh okay, I think I understand this better thank you!

14. jdoe0001

yw