# trig/cal

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how does pih^3/12 simplify to pih^2/4?

If you divide denominator by 3 you get 4 and then I guess the 3 goes away leaving a 2? But if this is correct why does this work?

• trig/cal -

Did you do the anti-derivative?

INT PI*H^2/4 dh = PI H^3/12

and likewise,

d/dh (PI H^3/12)= PI H^2/4

• trig/cal -

no i took the derivative. i see now
d/dh (PI*h^3/12) = 3PI*h^2/12 = PI*h^2/4

sorry i guess this was the wrong forum

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