Recent content by mk200789

really? ohkay~

Homework Statement let r = sin(t)+ cos(t) sketch the graph Homework Equations The Attempt at a Solution i really don't know how to start this off. i know some working should be done in order to sketch it but what?

thanks. yeh i was told to use trig sub:)

SO...my working so far is correct? or the prof's correct?:|

Homework Statement integrate (x^3)sqrt(x^2 + 8) dx Homework Equations The Attempt at a Solution let x = 2sqrt(2)tan(t) ==> dx= 2sqrt(2)sec^2(t) dt =int (x^3)sqrt(x^2 + 8) dx =int (16sqrt(2)tan^3(t)) sqrt(8tan^2(t) + 8) (2sqrt(2)sec^2(t)) dt =int (32 sqrt(2)) (tan^3(t))...

ttthank you!

Homework Statement integrate tan(x)sec^4(x) dx Homework Equations The Attempt at a Solution int tan(x)sec^4(x) dx = int tan(x)sec^2(x)sec^2(x) dx = int tan(x)sec^2(x) (tan^2(x)+1) dx let u = tanx ==> du = sec^2(x) dx = int usec^2(x) (u^2 + 1) /sec^2(x) du = int u(u^2+1)...