I SERIOUSLY don't understand increasing/decreasing functions!?

This might help you understand further

I'll leave to let Molly explain it so that you don't have two people saying things.

Both functions have increasing and decreasing sections. When it slopes upwards (positive gradient) it is increasing, when it slopes downwards (negative gradient) it is decreasing.

Your confusion is because the graphs you have shown are the graphs of the derivative - i.e the gradient. To make this clearer you should draw the graph of the original equation, to the same scale, and compare it to that of the gradient. You'll find that where the original graph slopes upwards, the gradient graph will be positive, and where the original graph slopes downwards, the gradient graph will be negative.

In the example you posted the original graph is: y = x^3 + 5x^2 - 8x +1, and the gradient graph is: y = 3x^2 + 10x -8

I see, thank you soo much to both of you!!

This might seem slightly patronising - but I'm really just trying to help.

Do you want to test your understanding of increasing decreasing function by telling me for what values of $x$ is $y = (x-5)(x-2) = x^2 - 7x + 10$ is

1. $y$ increasing.
2. $y$ decreasing.

Naah, that's totally fine, thaanx for helping!!
Okay, so here's my solution.

Perfect!

Quick bit of trivia: the function is decreasing up to its minimum point, and then increases after it.

Can you see how the term 'stationary point' refers to the minimum point now?

Yeep! Thaanx once again!