Voume HSC question (1 Viewer)

[BlueGas]

I'm kind of confused with this question? Why did the sample answers multiple Pi by 2? And why weren't the b and a values Pi/3 and -Pi/3 respectively?

 

[nisak]

you can either to the volume from -pi/3 to pi/3
but since the graph is identical on both sides you can just do from 0 to pi/3 and then just times it by two. you get the same answer either way

 

[BlueGas]

you can either to the volume from -pi/3 to pi/3
but since the graph is identical on both sides you can just do from 0 to pi/3 and then just times it by two. you get the same answer either way

Ah okay, thanks!

 

[Silly Sausage]

Since y=sec(x) is an even function, the area from O to pi/3 can be doubled.

This does not apply for all functions that are "identical" to each other on both sides. Make sure to check if it's even or odd.