Calculus 2 - Integration: Finding the Area Between Curves (13 of 22) Finding the Limits of Integral

[@ScottNguyenRCAC]

Your video should have more views and likes.

[@lillyzegarra8025]

Dude your y=x^2-4 is incorrect, you're a bad robot. The -4 indicates that you should start the parabola lower at (0,-4). Please respond, thank you.

[@MichelvanBiezen]

"dude" "you're a bad robot" Seems a bit disrespecful. (the video is correct as is)

[@lillyzegarra8025]

@@MichelvanBiezen You're right, I must've been distracted and solved for y=x^2-4 when I should've solved for y=X^2-4x. My bad Mr. Biezen, you still rock!

[@arjunchandgude7998]

My exam is tomorrow and this saved my life.

[@MichelvanBiezen]

Good luck on your exam.

[@soutlykuoyhay8583]

how do i know, its y1 or y2?

[@MichelvanBiezen]

You can label them any way you like. You can reverse the label, but then you will have to reverse the integrand as well.

[@danmoua7686]

Shouldnt Y(2) be (x^(2)-4)?

[@mikekastner5402]

x equals 0 and x equals 4, not 2 as you stated on the parabola at 5 minutes into the video

[@MichelvanBiezen]

The statement in the video was correct. Thanks for checking.

[@tms174]

@Michael van Biezen, shouldn’t the quadratic equation have its zero points at (0,4), instead of (0,2)? My logic: If you let y be equal to 0, you can factorize the equation into 0=x*(x-4) or 0=x and 0=x-4 Resulting in y being 0 at x=0 and x=4. Checked it too with a solver. Thank you in advance for taking your time to help!!

[@MichelvanBiezen]

The little lines on the x-axis do not have values assigned and are not unitary values. The quadratic equation does indeed cross the x-axis at x = 0 and x = 4. Note that the the intersection with the line is at x = 6 which is about 3/2 the distance where the quadratic equation crosses the x-axis.

[@tms174]

@@MichelvanBiezen Thank you for that quick response. I noticed so too, however your commentary "+/-2" (0:40) apparently confused me. On another note: thank you for that concise video!

[@r.m8345]

But some of the area is negative doesn't that mean you're finding the net area not the total area am I right

[@MichelvanBiezen]

It depends on the problem, and what it represents. Sometimes you want the "net" area and sometimes you want the total area.

[@perfectionist1337]

Such a life saver

[@MichelvanBiezen]

Glad it helped 🙂

[@cosmicbeth518]

Why is there no plus c when you integrate?

[@MichelvanBiezen]

If you calculate a definite integral (an integral that has an upper and lower limit), the constant of integration cancels out.

[@cosmicbeth518]

@@MichelvanBiezen ahhh right, thank you! Dunno why I didnt realise that 😅

[@asiyayesmin1508]

Sir can you please teach me .

[@MichelvanBiezen]

Hopefully the videos are helping.