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C4 Integration help

Stuck on this one

By integration, find an exact value for the area

How would i integrate the second function, i dont seem to be getting anywhere with parts:s-smilie:

Can someone help me please

thanks

π3π29tsintdtπ3π212sin2tcostdt \int^\frac{\pi}{2}_\frac{\pi}{3} 9tsint dt - \int^\frac{\pi}{2}_\frac{\pi}{3}12sin^2tcostdt
Reply 1
devan5


π3π29tsintdtπ3π212sin2tcostdt \int^\frac{\pi}{2}_\frac{\pi}{3} 9tsint dt - \int^\frac{\pi}{2}_\frac{\pi}{3}12sin^2tcostdt

Susbtitution of u=sin(t) will work or just look at the derivative of sin3(t) sin^3(t)
for the last bit sin^2t is 1 - cos^2t so sub it in

for the first bit do integration by parts
Reply 3
First integral by parts, second by inspection. Simples.
Reply 4
As far as C4 goes, then take the first comment, u=sint for the second integral
Reply 5
By inspection. Notice that you're integrating a function and its derivative
Reply 6
So will it be 4sin3t 4sin^3t
Reply 7
:yes:
Reply 8
Thanks Tsr:woo:
devan5
Stuck on this one

By integration, find an exact value for the area

How would i integrate the second function, i dont seem to be getting anywhere with parts:s-smilie:

Can someone help me please

thanks

π3π29tsintdtπ3π212sin2tcostdt \int^\frac{\pi}{2}_\frac{\pi}{3} 9tsint dt - \int^\frac{\pi}{2}_\frac{\pi}{3}12sin^2tcostdt


the second equation you basically follow the chain rule (from differentiation) but in reverse.

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