AQA Core 3 7.03a Integration by Substitution: Indefinite Integrals

[billycaiger]

Jack Brown you are genuinely an absolute legend! I have pretty much watched all of your core and stats videos over the past 2 years and without them I would be no where near the level of maths I am today! Thank you!!!

[ItsAsianTV]

I love this guy. I want to come to your sixth form 😂

[FPSFGaming]

Hi, I'm struggling to understand why around 8:25 you just took the 2/9 outside of the integral? Isn't that a coefficient, and consequently a necessary part inside the integration?

[billysmith]

That was the explanation I was looking for; thank you :) I'm still just a little confused with the whole multiplying the dx business. I've always been taught that the dy/dx was a symbol much like those for multiplication etc. Why can it be treated as a fraction in this case?

[miano]

Hi! Great video! What happens if for the instance the x^2 doesn't cancel out in a question when we reach this stage for e.g ∫ 2x^2 (u^3) (1/9) du. Do we then integrate the 2/9x^2 separately?

[jinali]

you know in the first example, shouldn't it be = 1/6 (x-1)^5 not to the power of 6. I used reversing the chain rule to get the answer

[selenag]

Sorry I know I ask a lot of questions, but, if a question says integrate by substitution however you use the reverse chain rule, would you not get the marks?

[edwarda.]

How comes you are allowed to bring numbers such as 2/9 out of the integral?