Modelling with differentiation

[reef robin]

I don't understand the substitution in past a with theta

[grizzled oyster]

Wdym

Easier to do if you use radians

Area of sector is 1/2 r^2 theta

Then you can use theta to find perimeter

And replace with r

Also this is not differentiation

@reef robin

[reef robin]

We haven't learnt radians yet so

[reef robin]

Second question is, its in the differentiation exercise

[reef robin]

I'll just learn by myself

[reef robin]

Thanks

[dense plume]

It's just a conversion as simple as 180°=π rad

So you're usual exact angles of 30 45 60 90 become π/6 π/4 π/3 π/2

[gilded gorge]

@reef robin

Hope that helps

[reef robin]

Thanks for the help everyone