find power and energy delivered

the charge entering the positive terminal of an element is

while the voltage across the element (plus to minus) is

find the power delivered to the element at

so I did thus...

given that

then since

so at then

its obvioiusly not correct

the correct answer is 164.5mW

so somewhere??? also I didn't know what "plus to minus" meant... AC??

best to multiply the expresions of i(t) and v(t) first

Plugging in gives the correct result.

with *wolframalpha*

so it is best to multiply the expresions of i(t) and v(t) first before we apply the t=0.3s

agree about the () just wish this text book would do so it is confusing.. also like the [] around the units.

yes thnks for help...more EE ?? to come (Cool)